espouse vs fasten on

espouse and fasten on both are verbs.

Word	Noun	Adjective	Verb	Adverb
espouse	No	No	Yes	No
fasten on	No	No	Yes	No

As verbs, fasten on is a hyponym of espouse; that is, fasten on is a word with a more specific, narrower meaning than espouse:

espouse: take up the cause, ideology, practice, method, of someone and use it as one's own
fasten on: adopt

Other hyponyms of espouse include hook on, latch on, seize on, take up.

espouse (verb)	fasten on (verb)
take up the cause, ideology, practice, method, of someone and use it as one's own	adopt
choose and follow; as of theories, ideas, policies, strategies or plans
take in marriage; married