now vs directly

now is a noun but directly is not a noun.

Word	Noun	Adjective	Verb	Adverb
now	Yes	No	No	Yes
directly	No	No	No	Yes

As adverbs, now and directly are synonyms defined as:

now (noun)	directly (noun)
the momentary present

now (adverb)	directly (adverb)
in these times	without deviation
without delay or hesitation; with no time intervening	in a forthright manner; candidly or frankly
used to preface a command or reproof or request	without anyone or anything intervening
at the present moment	without delay or hesitation; with no time intervening
in the historical present; at this point in the narration of a series of past events
in the immediate past
(prefatory or transitional) indicates a change of subject or activity