look up any word, like cleveland steamer:
a helmet that people who work on construction sites wear, so shit doesnt fall on their head and kill them.
Mark: Holy shit Steve! Look out!
*Steve gets owned in the head by a brick*
Mark: Damn son, shoulda had your hard hat on!
by Kast March 31, 2006
1. a steel or plastic helmet worn to protect one's head from falling objects or debris.

2. a worker who wears a hard hat.
A hard hat is one tool that saves lives.
by Light Joker August 20, 2005
A thing that protects your head.
I wear a hardhat when i watch tv.
by Dee July 24, 2004
A comdom or anything that protects against pregnancy
Let's go baby I got my hard hat on and ready to beat them guts
by corey hockenberry October 02, 2006
Hard hat is a slang synonym for an erect penis.
For example "Honey i got a hard hat are you ready"
Or "hmmm this porn cause's meglo hard hat syndrome"
by Chris Woodruff August 18, 2006
1. a protective helmet, usually made of plastic worn by workers in places such as construction sites

2. a laborer who's job requires them to wear a hardhat, such as a construction worker
A hardhat is a must-have in professions where debree can cause injury.
by Light Joker October 18, 2006
To tuck your erection in the waistline of your pants in order to protect yourself from the embarrassment of a public boner.
John: Why is Joey walking so weird?
Jimmy: Because he's definitely Hard-Hating it right now!
by Dean0530 November 05, 2011