wifty can be another word for beast, sick, wicked and other words meaning cool or awesome things. it can also stand for White Inbred Fucking Tipsy Yaks. you can come up with something else that it stands for as long as the word yak or yaks is involved, (normally, actually forcibly as the last word)
"Hey dude, i just the most wifty thing EVER!"
"hey you guys, there's a wifty outside!"
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