tin ass 

Someone who achieves a feat of skill through nothing but luck

You landed that 3-pointer?! What a tin ass!

tin ass by tin ass September 10, 2003

Tin ass 

Do have been shagged by so many sheep that your behind begins to take on a dark shade of grey resembling tin.

Man: That tokoroan lad is a bit of a tin ass.

Tin ass by Tui_Pure3 July 16, 2011

ass over tin cups 

To fall in a very serious but yet very funny way

" You shoulda seen that moron, he was walking down the hill and went ass over tin cups "

ass over tin cups by vwaynev June 16, 2008

Tinass 

A person who refuses to shout a round of beers. Guys named Benny or Rory are often referred to as tinass. There credit cards are covered in dust and often their wallets are brand new because no money has ever been inside.
A Tinass is the first person to yell “I’ll have one” then fades into the background come next round.

“oi Ben ya Tinass!!”

Tinass by TinassHunter October 28, 2017