(skateboarding) A trick where the skateboarder skates over a bent pole.

(climbing) A climbing technique where the fist is forced into a crack and clenched.

plural of jam sandwich

plural of jam tart

plural of jam session

(idiomatic) Promised benefits that never arrive. / (idiomatic, economics, by extension) Availability of a resource at a future date.

(slang, vulgar) A sanitary towel.

plural of jam rag

(idiomatic, informal) Money made very easily.

(roller derby) A period during which only one jammer is on the track.