A piece of headgear made from one or more sheets of tin foil, aluminium foil, or other similar material, especially when worn in the belief that it shields the brain from electromagnetic fields, or against mind control and/or mind reading.

Any of several hats made from paper; especially ones made from crepe paper as a party novelty, or ones constructed from newspaper and traditionally worn by printers

A broad-brimmed hat worn by cowboys, ranchers, and farmers, common in the western United States and Mexico.

(idiomatic) A good person; a hero. / (computing, slang) A well-meaning hacker who hacks for a good cause or to aid a company, organization, or government without causing harm. / (slang) A sailor.

A wide-brimmed ventilated sunhat worn in subtropical regions.

An insulating hat with one or more decorative pieces of spherical fluff at the peak.

(idiomatic) A gesture of acknowledgement; often, an expression of gratitude; originally by doffing one's hat.

A broad-brimmed felt hat worn by soldiers, often with a clasp on the left side to allow a rifle to be carried over the shoulder.

Alternative spelling of hat trick

Alternative form of deerstalker hat