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 except target color(s) like a filter does, a blocker lets everything else pass and blocks only the color(s) specified. Mobile phone jammer, technology which blocks telecommunications Blocker (roller derby)'s a position in roller… (More on Blocker)