COSH is an acronym for 'Criminal Offense Safety Helmet, ' which is a type of protective headgear worn by police officers. The term can also refer to a TRUNCHEON, which is a short club or baton used by law enforcement as a less-than-lethal weapon. A SAP is another type of less-than-lethal weapon, which is a flat, leather-covered lead weight with a handle. Both the TRUNCHEON and the SAP are commonly used by police officers to subdue suspects.