Wanker

During a deep & meaningful session at the local pub, the term wanker was raised (as oft is in a pub). The the lads, showing an unprecedented interest in the origins of our language wondered how the term had come about. (No pun intended).

Anyway, we all presumably know what the act of wanking is, but the question raised was, why is this seen as derogatory when it's such a common activity? And therefore, why has the term wanker come to mean someone who is a well errr wally?

Originally wanker means someone who is lazy and actually had nothing to do with masturbating.
not too sure how the 2 words finally got asociated, maybe because if someone is lazy all they do is sit at home and.....