look up any word, like mexican microwave:
 
1.
out of fashion or obsolete
bell bottom jeans and elevator shoes were considered old hat at one time, but now they're back in style.
by polo June 01, 2005
 
2.
Refered to when something has been brought up, or posted on forum multiple times.
"this is such an old hat, find something original"
by Chris February 14, 2005
 
3.
Something so well known and established that its practice isn't anything novel or interesting.
Knock knock jokes are rather old hat nowadays.

Picking up girls at clubs is old hat for him.
by tehdang February 14, 2014
 
4.
Vulva or vagina, esp. of a lady the senior side of 35. Popular term in the Victorian era.
Be careful dismounting that boneshaker, Delilah, lest the world and his dog see your old hat.
by Shenny February 22, 2014
 
5.
someone that is a bit emo. could possibly be a lesbian, due to quirkiness. loves panic at the disco. has never read "where the wild things are", and plays bass for rockband.
That girl Maegan, she's old hat! Just look at her!
by kmania November 15, 2009
 
6.
An little old woman in a HUGE old car wearing a big floppy hat, the hat is about all you can see behind the wheel of the gigantic car.
Be careful when traveling the Garden State Parkway down the shore, you're sure to run into an old hat or two!
by bigredchevytruck June 09, 2009
 
7.
A previously worn condom.
I couldn'y find a new one, so I used the old hat from last night.
by Brett Calvin September 30, 2006