to avoid doing something you have promised to do, especially not to pay a debt
Marty got his thumbs broken by Vito after he welched on a gambling debt.
contractorpeonによって 2005年03月02日(水)
To "black flag".

Meaning to make a bet, and lose it. Then not follow through with the consequences.
YOU: "I'll make a bet that Carlton suck and miss the 8, loser has to suck Suzis penis."

BlackFlag: "Carlton will win the premiership you douche, i'll take your bet"

Carlton go on to stink up the entire competition, blackflag loses the bet, and ignores that the bet was ever placed. Making him a dirty welch and the lowest form of life in the universe.
Blissidによって 2010年04月28日(水)
To welch. To go back on your word. A highly derogatory word made popular through the be-mag messageboard crew in response to wirolla's act of cowardice.
Wirolla had two options; tits or GTFO. He welched, he chose the second option.
gatsby.によって 2008年09月04日(木)
A bear
The Welch ate the human that got too close to its cubs.
tittieballsによって 2011年01月26日(水)
To masturbate in public with intent to be caught.
Watch the door im going to welch
zhawkによって 2013年05月21日(火)
a term of measurement for tea.
This bottle contains two welchs of tea.
danbartonによって 2009年04月01日(水)
purple weed. ie: grapes.
Yo, I got dem welches!
Lowkiによって 2006年04月28日(金)