plan vs mastermind

plan and mastermind both are nouns.

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

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

plan (noun)	mastermind (noun)
scale drawing of a structure	someone who creates new things
a series of steps to be carried out or goals to be accomplished	someone who has exceptional intellectual ability and originality
an arrangement scheme

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