agenda vs plan

agenda and plan both are nouns.

Word	Noun	Adjective	Verb	Adverb
agenda	Yes	No	No	No
plan	Yes	No	Yes	No

As nouns, plan is a hypernym of agenda; that is, plan is a word with a broader meaning than agenda:

Other hypernyms of agenda include program, programme.

agenda (noun)	plan (noun)
a temporally organized plan for matters to be attended to	scale drawing of a structure
a list of matters to be taken up (as at a meeting)	a series of steps to be carried out or goals to be accomplished
	an arrangement scheme

agenda (verb)	plan (verb)
	make plans for something
	have the will and intention to carry out some action
	make or work out a plan for; devise