n A potent, relatively cheap, addictive variety of cocaine; often a rock, usually smoked through a crack-pipe.
n (Northern England|Scotland|Ireland) Conviviality; fun; good conversation, chat, gossip, or humourous storytelling; good company.
n (computing) A program or procedure designed to circumvent restrictions or usage limits on software.
v (intransitive|of a pubescent boy's voice) To alternate between high and low register in the process of eventually lowering.
v (transitive|chemistry|informal) To break down (a complex molecule), especially with the application of heat: to pyrolyse.