Originally derived in Ceylon as a term to describe a fling or romantic escapade, it has rapidly evolved to become a verb with multiple uses, meaning anything from sexual intercourse (chussing) to urination (chus), a useless bugger (chusser) or an undefined waste of time (chus). In a certain sense, it is similar to fuck, but less taboo.
Users of chus are welcome to be creative in its use, but it can never be used as an adjective.
"I'd like to chus him/her" (I'd like to get it on with him/her)
"What did we do yesterday? Oh we just went to the park for a chus" (we went to the park for a loaf)
"I've got to go to the 'loo to put a chus"
"Don't come in here, we're chussing!"
"Oh chus!" or "Chus!!" (oh dear! / oh bugger!)
"I didn't get anything done today. I went to work and chussed about all day long"