Short for
Working Man, it is also usually accompanied by making the symbol for the W and M with your hands, the W is made by holding the Right hand upwards with the index, middle and ring finger all outstretched and spread apart, then the same with the left hand apart from poining it downwards.
Its used mainly to make fun of your friends who bitch and moan
all the time like
little girls about how hard they have been working
Scott: "Dude im so fucking tired, ive been
working like a slave all week"
All his mates sing the chorous: "hes a
Working Man, or the
Working People(whilst all making the WM sign with their hands to mock him)