trebucket vs trebuchet

trebucket and trebuchet both are nouns.

Word	Noun	Adjective	Verb	Adverb
trebucket	Yes	No	No	No
trebuchet	Yes	No	No	No

As nouns, trebucket and trebuchet are synonyms defined as:

trebucket and trebuchet: catapult that uses a swinging arm to throw a projectile

trebucket (noun)	trebuchet (noun)
catapult that uses a swinging arm to throw a projectile	catapult that uses a swinging arm to throw a projectile