moniker vs byname

moniker and byname both are nouns.

Word	Noun	Adjective	Verb	Adverb
moniker	Yes	No	No	No
byname	Yes	No	No	No

As nouns, moniker and byname are synonyms defined as:

moniker and byname: a familiar name for a person (often a shortened version of a person's given name)

Other synonyms of moniker include cognomen, nickname, sobriquet, soubriquet.

moniker (noun)	byname (noun)
a familiar name for a person (often a shortened version of a person's given name)	a familiar name for a person (often a shortened version of a person's given name)