- Generally a term used to describe one's anus (a.k.a arse hole)

- Comes from the word gash - which is a slang word for a vagina

- Back Gash is a term is often used by gay men.
Gay 1: How was last nighe?
Gay 2: Good, but my back gash is really sore! He was HUGE!

'I shouldn't have had that indian food last night, my back gash is killing me'
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something or (someone) that is so completely and utterly gash, they qualify for gash back. in short, gash of epic proportions. or just generally a term for skanks, who spend the majority of their time on their backs.
you're more than a slut, you're a walking gash back.

OR

stop talking shit, i didn't ask for gash back.
by XxDxX June 28, 2007
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A flash back of some memorable gash a.k.a vagina. Was first coined at 4:25am on the 5th of december 2011.
e.g. I'm having a gash-back

simular useage to flash back but only refers to gash.
by Kai-pachi December 6, 2011
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