sidesman vs assistant

sidesman and assistant both are nouns.

Word	Noun	Adjective	Verb	Adverb
sidesman	Yes	No	No	No
assistant	Yes	Yes	No	No

As nouns, assistant is a hypernym of sidesman; that is, assistant is a word with a broader meaning than sidesman:

sidesman: (Church of England) an assistant to the churchwarden; collects offerings of money in the church
assistant: a person who contributes to the fulfillment of a need or furtherance of an effort or purpose

Other hypernyms of sidesman include help, helper, supporter.

sidesman (noun)	assistant (noun)
(Church of England) an assistant to the churchwarden; collects offerings of money in the church	a person who contributes to the fulfillment of a need or furtherance of an effort or purpose

sidesman (adjective)	assistant (adjective)
	of or relating to a person who is subordinate to another