digest vs apprehend

digest is a noun but apprehend is not a noun.

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

As verbs, apprehend is a hypernym of digest; that is, apprehend is a word with a broader meaning than digest:

Other hypernyms of digest include compass, comprehend, dig, get the picture, grasp, grok, savvy.

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

digest (verb)	apprehend (verb)
make more concise	get the meaning of something
systematize, as by classifying and summarizing	take into custody
become assimilated into the body	anticipate with dread or anxiety
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