delay vs postponement

delay and postponement both are nouns.

Word	Noun	Adjective	Verb	Adverb
delay	Yes	No	Yes	No
postponement	Yes	No	No	No

As nouns, postponement is a hyponym of delay; that is, postponement is a word with a more specific, narrower meaning than delay:

delay: the act of delaying; inactivity resulting in something being put off until a later time
postponement: act of putting off to a future time

As nouns, delay and postponement are synonyms defined as:

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

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

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