plan of action vs plan

plan of action and plan both are nouns.

Word	Noun	Adjective	Verb	Adverb
plan of action	Yes	No	No	No
plan	Yes	No	Yes	No

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

Other hypernyms of plan of action include program, programme.

plan of action (noun)	plan (noun)
a plan for actively doing something	scale drawing of a structure
	a series of steps to be carried out or goals to be accomplished
	an arrangement scheme

plan of action (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