schoolmate vs schoolfellow

schoolmate and schoolfellow both are nouns.

Word	Noun	Adjective	Verb	Adverb
schoolmate	Yes	No	No	No
schoolfellow	Yes	No	No	No

As nouns, schoolmate and schoolfellow are synonyms defined as:

Other synonyms of schoolmate include class fellow, classmate.

schoolmate (noun)	schoolfellow (noun)
an acquaintance that you go to school with	an acquaintance that you go to school with