(informal) Someone with exceptional skills in a certain field.

A type of firefighter highly skilled in wildfire firefighting without external support, using basic tools that are backpacked in and manhandled about.

(US, rail transport) A fast freight train.

(slang) A dose of recreational drugs deliberately laced with poison.

(transitive, slang) To give (somebody) a dose of recreational drugs deliberately laced with poison.

(informal) Highly skilled.

(informal) Displaying talent.