Toothy describes a smile that prominently shows the teeth, usually in a big, enthusiastic way. When someone flashes a toothy grin, you see lots of their teeth because they're smiling so widely. Politicians often give toothy smiles in photographs, showing all their teeth to look friendly and confident.

The word can also describe animals with prominent or impressive teeth. A shark has a toothy mouth full of sharp, visible teeth. An alligator's toothy jaw is one of its most recognizable features.

Sometimes toothy suggests something slightly exaggerated or overdone. A toothy smile might seem genuine and warm, or it might feel a bit forced, like someone trying too hard to look cheerful for a school picture. The context usually makes the difference clear: your best friend's toothy smile when you arrive at their birthday party feels completely different from a salesperson's toothy grin when they're trying to sell you something.