A large group of chavs. Chavs have adapted to a pack mentality and therefore move in groups of common stupidity. The word is a combination of Chav and Avalanche.
“Wow, it’s so scenic and quiet here”
“Not for much longer. There’s a chavalanche approaching”
The immediate period after Townie pubs and clubs kick out at the Weekend when hundreds of chavs fall out of the establishment to fight, copulate and inbreed.
Police officer 1: Well Lenny I think we're going to have a right chavalanche on our hands tonight when Evolutionkicks out!
Police officer 2: Lets hope so Dave I cant wait to take afew of those grubby little Pikey Fuckers.
A large group of chavs and chavettes walking down the street or hanging around on a street corner, smoking and sometimes drunk. Like an avalanche, you may get swallowed up bt the crowd, and possibly killed by the cloud of smoke and cheap perfume that lingers! It is recomended to stay away if at all possible!
'look out mate'
'what'
'that, quick run!'
'help us...chav-alanche!!'
The act of one's rectum muscles relaxing so completely that feces flows out without any effort or control devastating all in its path like an avalanche.
ohhhh bro after eating that taco I was hit with a series of shavalanches all night long.