noun
: an automobile exhaust-system component containing a catalyst which causes conversion of harmful gases (as carbon monoxide and uncombusted hydrocarbons) into mostly harmless products (as water and carbon dioxide)
noun
: an automobile exhaust-system component containing a catalyst which causes conversion of harmful gases (as carbon monoxide and uncombusted hydrocarbons) into mostly harmless products (as water and carbon dioxide)
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012