Noun:
1: now the momentary present; "Now is a good time to do it"; "it worked up to right now"
Adverb:
1: at present, now 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"
2: nowadays, now, today 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"
3: now 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: now (prefatory or transitional) indicates a change of subject or activity; "Now the next problem is..."
5: now used to preface a command or reproof or request; "now hear this!"; "now pay attention"
6: right away, like a shot, now, at once, directly, straightaway, in real time, straight off, immediately, instantly, forthwith 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!"
7: now in the immediate past; "told me just now"