General:
* A hat in hand: Meaning to be humble or apologetic.
* Pass the hat: To ask for donations.
* Throw your hat in the ring: To enter a competition or contest.
* Wear many hats: To have many roles or responsibilities.
* Hats off to: To express admiration or respect for someone.
Figurative:
* Put your thinking cap on: To think hard about something.
* Under the hat: Something done in secret.
* Have a hat full of: To have a lot of something.
* A chip on your shoulder: To be easily offended or angry.
* Pull the wool over someone's eyes: To deceive someone.
Idioms:
* A hat trick: To score three goals in a single game.
* Old hat: Something that is no longer fashionable or interesting.
* Not my cup of tea: Not something I like or am interested in.
* Up in the air: Uncertain or undecided.
* Keep your hat on: To be patient or wait.
Specific:
* A wide-brimmed hat: A hat with a wide brim.
* A straw hat: A hat made of straw.
* A baseball cap: A hat worn by baseball players.
* A top hat: A tall, formal hat.
* A beanie: A knitted hat that covers the ears.
These are just a few examples, and there are many other phrases that use the word "hat." The meaning of the phrase often depends on the context in which it is used.