hautboy vs hautbois

hautboy and hautbois both are nouns.

Word	Noun	Adjective	Verb	Adverb
hautboy	Yes	No	No	No
hautbois	Yes	No	No	No

As nouns, hautboy and hautbois are synonyms defined as:

hautboy and hautbois: a slender double-reed instrument; a woodwind with a conical bore and a double-reed mouthpiece

Other synonyms of hautboy include oboe.

hautboy (noun)	hautbois (noun)
a slender double-reed instrument; a woodwind with a conical bore and a double-reed mouthpiece	a slender double-reed instrument; a woodwind with a conical bore and a double-reed mouthpiece