sobriquet vs soubriquet

sobriquet and soubriquet both are nouns.

Word	Noun	Adjective	Verb	Adverb
sobriquet	Yes	No	No	No
soubriquet	Yes	No	No	No

As nouns, sobriquet and soubriquet are synonyms defined as:

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

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

sobriquet (noun)	soubriquet (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)