Definitions by Hackney yout'

GCS 

A shortened version of General Chirpsing Skills, that was coined by the badass youth of Hackney, London.

If a boy is chatting up a girl and his friends see they may state 'GCS'

Dude how did you get that girl?" "I've Been working on my GCS

GCS by Hackney yout' February 20, 2011