キャップ

A plain soft hat with a rounded crown and a stiff bill. Most often shown in a shade of blue and displayed at an angle to clearly display its outwards- protruding bill.

Regularly associated with the slang term "capping", meaning "lying". Responding to a message with a single 🧢 emoji is viewable as an accusation of lying (“cap”) while stating "no 🧢" ("no cap") is intended to emphasize the truthfulness of a statement.