Blocker can mean any of the following: Blocker (ice hockey equipment) The nickname of Steve Roach, Australian rugby league footballer Blocker (cricket), slang for a defensive-minded batsman in cricket The inverse of a filter (optics). Instead of blocking everything like a filter does, it lets everything else pass and blocks only the things specified. Mobile phone jammer, technology which blocks telecommunications Blocker (roller derby) is a position in roller derby. Terry Blocker is a form… (More on Blocker)