slang The mouth of someone who has dental braces. Also used as a mocking nickname. I never used to smile for photos when I was in middle school because I hated the way my tinsel teeth looked. Nice smile, tinsel teeth! Don't get too close to any magnets, or your face'll get stuck!
n. a nickname for someone who wears dental braces. (Also a rude nickname.) Well, tinsel-teeth, today’s the day your braces come off.