choirmaster vs cantor

choirmaster and cantor both are nouns.

Word	Noun	Adjective	Verb	Adverb
choirmaster	Yes	No	No	No
cantor	Yes	No	No	No

As nouns, choirmaster and cantor are synonyms defined as:

Other synonyms of choirmaster include precentor.

choirmaster (noun)	cantor (noun)
the musical director of a choir	the official of a synagogue who conducts the liturgical part of the service and sings or chants the prayers intended to be performed as solos
	the musical director of a choir