Source : Webster's Revised Unabridged Dictionary (1913)

Now \Now\, adv. [OE. nou, nu, AS. n[=u], nu; akin to D., OS., &
   OHG. nu, G. nu, nun, Icel., n[=u], Dan., Sw., & Goth. nu, L.
   nunc, Gr. ?, ?, Skr. nu, n[=u]. [root]193. Cf. {New}.]
   1. At the present time; at this moment; at the time of
      speaking; instantly; as, I will write now.

            I have a patient now living, at an advanced age, who
            discharged blood from his lungs thirty years ago.
                                                  --Arbuthnot.

   2. Very lately; not long ago.

            They that but now, for honor and for plate, Made the
            sea blush with blood, resign their hate. --Waller.

   3. At a time contemporaneous with something spoken of or
      contemplated; at a particular time referred to.

            The ship was now in the midst of the sea. --Matt.
                                                  xiv. 24.

   4. In present circumstances; things being as they are; --
      hence, used as a connective particle, to introduce an
      inference or an explanation.

            How shall any man distinguish now betwixt a parasite
            and a man of honor ?                  --L'Estrange.

            Why should he live, now nature bankrupt is ? --Shak.

            Then cried they all again, saying, Not this man, but
            Barabbas. Now, Barabbas was a robber. --John xviii.
                                                  40.

            The other great and undoing mischief which befalls
            men is, by their being misrepresented. Now, by
            calling evil good, a man is misrepresented to others
            in the way of slander.                --South.

   {Now and again}, now and then; occasionally.

   {Now and now}, again and again; repeatedly. [Obs.] --Chaucer.

   {Now and then}, at one time and another; indefinitely;
      occasionally; not often; at intervals. ``A mead here,
      there a heath, and now and then a wood.'' --Drayton.

   {Now now}, at this very instant; precisely now. [Obs.] ``Why,
      even now now, at holding up of this finger, and before the
      turning down of this.'' --J. Webster (1607).

   {Now . . . now}, alternately; at one time . . . at another
      time. ``Now high, now low, now master up, now miss.''
      --Pope.

Now \Now\, a.
   Existing at the present time; present. [R.] ``Our now
   happiness.'' --Glanvill.

Now \Now\, n.
   The present time or moment; the present.

         Nothing is there to come, and nothing past; But an
         eternal now does ever last.              --Cowley.

Source : WordNet®

now
     n : the momentary present; "Now is a good time to do it"; "it
         worked up to right now"

now
     adv 1: at the present moment; "goods now on sale"; "the now-aging
            dictator"; "they are now abroad"; "he is busy at
            present writing a new novel"; "it could happen any
            time now" [syn: {at present}]
     2: in these times; "it is solely by their language that the
        upper classes nowadays are distinguished"- Nancy Mitford;
        "we now rarely see horse-drawn vehicles on city streets";
        "today almost every home has television" [syn: {nowadays},
         {today}]
     3: in the historical present; at this point in the narration of
        a series of past events; "President Kennedy now calls in
        the National Guard"; "Washington now decides to cross the
        Delaware"; "the ship is now listing to port"
     4: (prefatory or transitional) indicates a change of subject or
        activity; "Now the next problem is..."
     5: used to preface a command or reproof or request; "now hear
        this!"; "now pay attention"
     6: without delay or hesitation; with no time intervening; "he
        answered immediately"; "found an answer straightaway"; "an
        official accused of dishonesty should be suspended
        forthwith"; "Come here now!" [syn: {immediately}, {instantly},
         {straightaway}, {straight off}, {directly}, {right away},
         {at once}, {forthwith}, {in real time}, {like a shot}]
     7: in the immediate past; "told me just now"