time lag vs delay

time lag and delay both are nouns.

Word	Noun	Adjective	Verb	Adverb
time lag	Yes	No	No	No
delay	Yes	No	Yes	No

As nouns, time lag and delay are synonyms defined as:

Other synonyms of time lag include hold, postponement, wait.

time lag (noun)	delay (noun)
time during which some action is awaited	the act of delaying; inactivity resulting in something being put off until a later time
	time during which some action is awaited

time lag (verb)	delay (verb)
	cause to be slowed down or delayed
	stop or halt
	slow the growth or development of
	act later than planned, scheduled, or required