ache vs comprehend

ache is a noun but comprehend is not a noun.

Word	Noun	Adjective	Verb	Adverb
ache	Yes	No	Yes	No
comprehend	No	No	Yes	No

As verbs, comprehend is a hypernym of ache; that is, comprehend is a word with a broader meaning than ache:

Other hypernyms of ache include perceive.

ache (noun)	comprehend (noun)
a dull persistent (usually moderately intense) pain

ache (verb)	comprehend (verb)
have a desire for something or someone who is not present	get the meaning of something
be the source of pain	to become aware of through the senses
feel physical pain	include in scope; include as part of something broader; have as one's sphere or territory