delay vs shelve

delay is a noun but shelve is not a noun.

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

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

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

delay (verb)	shelve (verb)
cause to be slowed down or delayed	place on a shelf
stop or halt	hold back to a later time
slow the growth or development of
act later than planned, scheduled, or required