Gash up 

To act like your brave when your really a coward.

Yo you wanna Gash up I'll run up on ya too.

Gash up by thahib December 4, 2019

Gash warmed up in the microwave 

An expression of something very shit.
Usually related to the way someone is feeling.

Person 1 - How you feeling after your night out?
Person 2 - Ohh mate, i feel like gash warmed up in the microwave.

Mate you forgot your keys....
OH GASH WARMED UP IN THE MICROWAVE!!

Gash warmed up in the microwave by Stevie A May 25, 2008

Gash Mash-up 

When a person gets bored of one persons vagina so has to swap from fanny to fanny. Also if a person does not get action from his girlfriend or only once or twice a week so finds other girls so he can get gash all week.

Joe: Woww i've got a proper gash mash-up this week lillie on monday then ellie tuesday then my girlfriends sleeping over wednesday but friday i think i will see Georgie.

Jack: Ahh cant be arsed my girlfriends fanny is to tight i get bored might as well go fuck Georgie.

Gash Mash-up by sbvodka July 28, 2010