Here is a longer list using the following commands:

    A = WordList["KnownWords"];
    B = DeleteStopwords[A];
    c = Complement[A, B]
>    {
        a,
        A,
        about,
        above,
        across,
        A.D.,
        add-in,
        add-on,
        A.E.,
        after,
        again,
        against,
        a.k.a.,
        all,
        all-around,
        all-or-nothing,
        all-out,
        almost,
        alone,
        along,
        al-Qur'an,
        already,
        also,
        although,
        always,
        a.m.,
        A.M.,
        Am,
        AM,
        among,
        an,
        AN,
        and,
        and/or,
        another,
        any,
        anyone,
        anything,
        anywhere,
        A-one,
        are,
        around,
        as,
        As,
        AS,
        at,
        At,
        back,
        back-to-back,
        balls-up,
        bang-up,
        be,
        Be,
        beaten-up,
        beat-up,
        because,
        become,
        beefed-up,
        before,
        behind,
        being,
        belly-up,
        below,
        between,
        bicycle-built-for-two,
        blown-up,
        booze-up,
        born-again,
        both,
        bottom-up,
        boxed-in,
        break-in,
        bride-to-be,
        broken-down,
        brush-off,
        built-in,
        built-up,
        bundled-up,
        burned-out,
        burned-over,
        burnt-out,
        bust-up,
        but,
        button-down,
        buttoned-down,
        buttoned-up,
        by,
        by-and-by,
        call-back,
        caller-out,
        caller-up,
        call-in,
        call-out,
        camp-made,
        can,
        can-do,
        cared-for,
        carry-over,
        cast-off,
        change-up,
        check-in,
        ch'i,
        Ch'in,
        chin-up,
        chock-full,
        choke-full,
        chucker-out,
        chuck-full,
        churned-up,
        climb-down,
        clip-on,
        coach-and-four,
        comb-out,
        come-on,
        cover-up,
        crack-up,
        cure-all,
        custom-made,
        cut-in,
        cut-up,
        D.A.,
        dead-on,
        derring-do,
        do,
        DO,
        d.o.a.,
        do-it-yourself,
        done,
        do-nothing,
        do-si-do,
        down,
        Down,
        down-and-out,
        drawn-out,
        dressed-up,
        dried-out,
        dried-up,
        drive-in,
        drop-off,
        during,
        each,
        eighty-four,
        eighty-one,
        eighty-three,
        eighty-two,
        either,
        end-all,
        enough,
        even,
        ever,
        every,
        everyone,
        everything,
        everywhere,
        eyes-only,
        face-off,
        factory-made,
        fare-thee-well,
        far-off,
        far-out,
        few,
        fifty-four,
        fifty-one,
        fifty-three,
        fifty-two,
        fill-in,
        find,
        first,
        F.I.S.C.,
        flame-out,
        flare-up,
        fly-by,
        follow-on,
        follow-through,
        follow-up,
        for,
        force-out,
        fore-and-after,
        forget-me-not,
        form-only,
        forty-first,
        forty-four,
        forty-one,
        forty-three,
        forty-two,
        foul-up,
        four,
        frame-up,
        free-for-all,
        from,
        fucked-up,
        full,
        further,
        get,
        get-go,
        get-up-and-go,
        G.I.,
        gill-less,
        give,
        give-and-go,
        give-and-take,
        go,
        go-around,
        go-between,
        going-over,
        good-by,
        good-for-nothing,
        goof-off,
        groom-to-be,
        half-seas-over,
        hand-down,
        handed-down,
        hand-me-down,
        hands-down,
        hands-off,
        hands-on,
        hanger-on,
        hang-up,
        hard-on,
        has-been,
        have,
        have-not,
        Hawai'i,
        he,
        He,
        head-on,
        heads-up,
        heart-whole,
        her,
        here,
        Here,
        hers,
        herself,
        higher-up,
        high-interest,
        high-up,
        him,
        himself,
        his,
        hold-down,
        hollow-back,
        hoped-for,
        hopped-up,
        how,
        how-do-you-do,
        how-d'ye-do,
        however,
        HSV-I,
        hundred-and-first,
        hushed-up,
        i,
        I,
        I.D.,
        i.e.,
        I.E.D.,
        if,
        If,
        ill-being,
        in,
        In,
        IN,
        in-between,
        inside-out,
        interest,
        into,
        I.Q.,
        it,
        IT,
        its,
        itself,
        I.W.W.,
        jerk-off,
        Johnny-jump-up,
        jumped-up,
        keep,
        knock-down,
        knock-down-and-drag-out,
        knocked-out,
        know-all,
        know-how,
        know-it-all,
        ladder-back,
        laid-back,
        laid-off,
        lash-up,
        last,
        lay-by,
        lay-up,
        lead-in,
        lean-to,
        least,
        less,
        lie-in,
        lighting-up,
        lights-out,
        log-in,
        longed-for,
        looker-on,
        look-over,
        low-down,
        low-interest,
        lying-in,
        ma'am,
        machine-made,
        made,
        made-up,
        make-do,
        make-up,
        man-made,
        many,
        marked-up,
        match-up,
        matt-up,
        may,
        May,
        me,
        ME,
        mess-up,
        mid-May,
        mid-off,
        mid-on,
        might,
        might-have-been,
        mixed-up,
        mix-up,
        mock-up,
        more,
        More,
        most,
        mostly,
        much,
        must,
        my,
        myself,
        ne'er-do-well,
        never,
        never-never,
        Never-Never,
        new-made,
        next,
        next-to-last,
        ninety-four,
        ninety-one,
        ninety-three,
        ninety-two,
        no,
        No,
        no.,
        nobody,
        no-go,
        no-one,
        nor,
        no-show,
        nosh-up,
        not,
        nothing,
        now,
        nowhere,
        odds-on,
        of,
        off,
        off-and-on,
        often,
        on,
        once,
        once-over,
        one,
        one-and-one,
        one-off,
        one-on-one,
        one-to-one,
        only,
        OR,
        other,
        our,
        ours,
        ourselves,
        out,
        out-and-out,
        over,
        own,
        p.a.,
        P.A.,
        paid-up,
        part,
        passer-by,
        pass-through,
        paste-up,
        pegged-down,
        pent-up,
        per,
        perhaps,
        phase-out,
        phone-in,
        pick-me-up,
        pick-off,
        pig-a-back,
        pin-up,
        piss-up,
        plug-in,
        pop-up,
        Post-It,
        press-up,
        pull-in,
        pull-off,
        pull-through,
        pull-up,
        pumped-up,
        punch-up,
        purpose-made,
        put,
        put-down,
        put-on,
        put-put,
        put-up,
        put-upon,
        rake-off,
        raree-show,
        rather,
        rave-up,
        read-out,
        ready-made,
        right-down,
        right-side-out,
        right-side-up,
        rip-off,
        roll-on,
        run-down,
        run-in,
        runner-up,
        run-on,
        run-through,
        run-up,
        same,
        Same,
        Sana'a,
        sauce-alone,
        save-all,
        sawed-off,
        sawn-off,
        say-so,
        schoolma'am,
        see,
        seem,
        seeming,
        see-through,
        self-interest,
        self-made,
        self-will,
        send-off,
        set-back,
        set-to,
        seventy-four,
        seventy-one,
        seventy-three,
        seventy-two,
        seven-up,
        several,
        shake-up,
        shape-up,
        share-out,
        she,
        shell-less,
        shoo-in,
        shoot-down,
        shoot-'em-up,
        show,
        show-off,
        shut-in,
        side,
        side-to-side,
        since,
        sit-down,
        sit-in,
        sit-up,
        sixty-four,
        sixty-one,
        sixty-three,
        sixty-two,
        slap-up,
        slip-on,
        slip-up,
        smash-up,
        snarl-up,
        so,
        so-and-so,
        sold-out,
        some,
        someone,
        something,
        somewhere,
        so-so,
        sought-after,
        spaced-out,
        spend-all,
        spin-off,
        spread-out,
        stand-alone,
        stand-down,
        stand-in,
        stand-up,
        start-off,
        step-down,
        step-in,
        step-up,
        stick-on,
        still,
        stock-still,
        stock-take,
        stopped-up,
        straight-out,
        stripped-down,
        strung-out,
        stuck-up,
        such,
        sum-up,
        sure-enough,
        tailor-made,
        take,
        take-in,
        take-up,
        tap-off,
        teach-in,
        than,
        that,
        the,
        their,
        theirs,
        them,
        themselves,
        then,
        there,
        therefore,
        these,
        they,
        thing-in-itself,
        thirty-first,
        thirty-four,
        thirty-one,
        thirty-something,
        thirty-three,
        thirty-two,
        this,
        those,
        though,
        three,
        through,
        throw-in,
        thus,
        tie-in,
        tie-on,
        tie-up,
        time-out,
        tip-off,
        tip-up,
        to,
        to-do,
        toe-in,
        together,
        too,
        top-down,
        top-up,
        toss-up,
        touch-and-go,
        touch-me-not,
        toward,
        trade-in,
        trade-last,
        trade-off,
        tricked-out,
        trip-up,
        trumped-up,
        try-on,
        tumble-down,
        tune-up,
        turn-on,
        twenty-first,
        twenty-four,
        twenty-one,
        twenty-three,
        twenty-two,
        two,
        two-by-four,
        two-part,
        uncalled-for,
        uncared-for,
        under,
        unheard-of,
        unhoped-for,
        unlooked-for,
        unthought-of,
        until,
        unwished-for,
        up,
        up-and-down,
        upon,
        upside-down,
        us,
        US,
        U.S.A.,
        very,
        walk-in,
        walk-on,
        walk-through,
        walk-to,
        walk-up,
        warm-up,
        washed-out,
        washed-up,
        washing-up,
        wave-off,
        way-out,
        we,
        well,
        well-being,
        well-done,
        well-made,
        well-off,
        well-thought-of,
        well-to-do,
        what,
        when,
        where,
        where's,
        whether,
        which,
        while,
        whipper-in,
        white-out,
        who,
        WHO,
        whole,
        whom,
        whose,
        why,
        will,
        wished-for,
        with,
        within,
        with-it,
        without,
        work-in,
        worn-out,
        would-be,
        write-down,
        write-in,
        write-off,
        wrong-side-out,
        year-around,
        yearned-for,
        yet,
        you,
        you-all,
        your,
        yours,
        yourself
    }