abbreviate vs digest

abbreviate is not a noun while digest is a noun.

Word	Noun	Adjective	Verb	Adverb
abbreviate	No	No	Yes	No
digest	Yes	No	Yes	No

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

Other hyponyms of abbreviate include bowdlerise, bowdlerize, castrate, expurgate, shorten, concentrate, condense.

abbreviate (noun)	digest (noun)
	something that is compiled (as into a single book or file)
	a periodical that summarizes the news

abbreviate (verb)	digest (verb)
shorten	make more concise
reduce in scope while retaining essential elements	systematize, as by classifying and summarizing
	become assimilated into the body
	soften or disintegrate by means of chemical action, heat, or moisture
	soften or disintegrate, as by undergoing exposure to heat or moisture
	arrange and integrate in the mind
	put up with something or somebody unpleasant
	convert food into absorbable substances