power of appointment vs potency

power of appointment and potency both are nouns.

Word	Noun	Adjective	Verb	Adverb
power of appointment	Yes	No	No	No
potency	Yes	No	No	No

As nouns, potency is a hypernym of power of appointment; that is, potency is a word with a broader meaning than power of appointment:

power of appointment: authority given (in a will or deed) by a donor to a donee to appoint the beneficiaries of the donor's property
potency: the power or right to give orders or make decisions

Other hypernyms of power of appointment include authorisation, authority, authorization, dominance, say-so.

power of appointment (noun)	potency (noun)
authority given (in a will or deed) by a donor to a donee to appoint the beneficiaries of the donor's property	capacity to produce strong physiological or chemical effects
	the power or right to give orders or make decisions
	the state of being potent; a male's capacity to have sexual intercourse
	the inherent capacity for coming into being