undertake vs rent

undertake is not a noun while rent is a noun.

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

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

Other hyponyms of undertake include stipulate, sign, condition, qualify, specify, stipulate, lease, charter, hire, lease.

undertake (noun)	rent (noun)
	the act of rending or ripping or splitting something
	an opening made forcibly as by pulling apart
	a payment or series of payments made by the lessee to an owner for use of some property, facility, equipment, or service
	the return derived from cultivated land in excess of that derived from the poorest land cultivated under similar conditions

undertake (verb)	rent (verb)
promise to do or accomplish	engage for service under a term of contract
enter into a contractual arrangement	grant use or occupation of under a term of contract
enter upon an activity or enterprise	hold under a lease or rental agreement; of goods and services
accept as a charge	let for money
accept as a challenge