A smoker is a full-contact event generally held to prepare fighters before going into amateur competition. Smokers are generally inter-gym competitions rather than being between gymmates. Technically, smokers are illegal as they are unregulated and may or may not uphold athletic commission standards.
Also knows as: exhibitions, public sparring sessions
Edit: Sifu Z would like to point out that smokers generally include other activities such as strippers. They're also known to involve betting and excessive drinking and cigar smoking among the audience.