i know the word skanky-- but used to define beer that has gone bad-- either the stuff left over in the keg-- that you think might be drinkable-- or some beer you left at the summer house last fall-- that you convince yourself might be drinkable since its been "chilled' all winter in the unheated house--

you open the can/bottle-- and ugh!-- skanky beer! smells bad-- worse, vile, putrid-- enough to put you off beer for a while...