anything that can be nasty or deragatory. It's a sentence enhancer, you can replace it for almost anything. Usually is used for talking about farting or replacing the "S" word.
"Sorry guys i used all of the toilet paper because i had to take a major skeff."
"Dude, I have been skeffing all day, maybe i should go take a crap."
"My dog skeffed all over the floor because i forgot to take him outside."
skeff (pronounced SKEF/ˈskɛf/) — a Lincolnshire regional, informal insult meaning someone scruffy, sleazy, a bit gross or rough around the edges; can also mean a loud/coarse, socially unpleasant person.
West Midlands slang word for rockers, bikers, greasers etc. In the late 1980s it was used by the UK music press to refer to a specific scene centered around the bands Pop Will Eat Itself and Crazyhead. The term never found favour with readers of 'the inkies' (Sounds, Melody Maker and the still extant NME) and was soon dropped. Now often used in predominantly working-class areas of the midlands and the north to mean someone who listens to rock-derived music and/or dresses in a manner that suggests they affiliate themselves with rock music of some kind.
Some grebo passed with Sabbath playing on his stereo.
The Poppies are at no. 17? God, a grebo band in the charts!
They're playing nu-metal now, bloody grebos!