1. interjection of rebuke
The Collaborative International Dictionary of English v.0.48:
Now \Now\ (nou), 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. ny`, ny^n, Skr. nu, n[=u]. [root]193. Cf.
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.
2. Very lately; not long ago.
They that but now, for honor and for plate,
Made the sea blush with blood, resign their hate.
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.
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.
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."
WordNet (r) 3.0 (2006):
adv 1: interjection of rebuke