miter joint vs mitre joint

miter joint and mitre joint both are nouns.

Word	Noun	Adjective	Verb	Adverb
miter joint	Yes	No	No	No
mitre joint	Yes	No	No	No

As nouns, miter joint and mitre joint are synonyms defined as:

miter joint and mitre joint: joint that forms a corner; usually both sides are bevelled at a 45-degree angle to form a 90-degree corner

Other synonyms of miter joint include miter, mitre.

miter joint (noun)	mitre joint (noun)
joint that forms a corner; usually both sides are bevelled at a 45-degree angle to form a 90-degree corner	joint that forms a corner; usually both sides are bevelled at a 45-degree angle to form a 90-degree corner