Entry 2 senses Webster, 1913 Opener /ōp'-ən-ẽr/ · O·pen·er · IPA /ˈoʊ.pən.ɚ/ 01 n. One who, or that which, opens. 1. One who, or that which, opens. 2. A bottle opener or a can opener; as, you need an opener to get the cap off.