undertake vs subvention

undertake is not a noun while subvention is a noun.

Word	Noun	Adjective	Verb	Adverb
undertake	No	No	Yes	No
subvention	Yes	No	Yes	No

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

Other hyponyms of undertake include subvent, underwrite.

undertake (noun)	subvention (noun)
	the act or process of providing aid or help of any sort
	grant of financial aid as from a government to an educational institution

undertake (verb)	subvention (verb)
promise to do or accomplish	guarantee financial support of
enter into a contractual arrangement
enter upon an activity or enterprise
accept as a charge
accept as a challenge