enquirer vs questioner

enquirer and questioner both are nouns.

Word	Noun	Adjective	Verb	Adverb
enquirer	Yes	No	No	No
questioner	Yes	No	No	No

As nouns, enquirer and questioner are synonyms defined as:

Other synonyms of enquirer include asker, inquirer, querier.

enquirer (noun)	questioner (noun)
someone who asks a question	someone who asks a question