The black tar-like substance that scars the floors of your local fraternity. Frat Sludge is composed of beer, blood, sweat, seamen and hard work.
Mother of a Democrat!!!! I do declare, this Frat Sludge is very thick this fine evening!!
by Merry-am-WebStar October 23, 2011
1 more definition
the substance comprised of many unknown variables accumulated on the frat floor causing infection or death if not washed off immediately.
Aaron's head was covered with frat sludge after being tea bagged with paint!
by baker_292 April 28, 2008