Dictionary entry overview: What does pinnacle mean? • PINNACLE (noun) The noun PINNACLE has 3 senses: 1. (architecture) a slender upright spire at the top of a buttress of tower 2. the highest level or degree attainable; the highest stage of development 3. a lofty peak Familiarity information: PINNACLE used as a noun is uncommon. • PINNACLE (verb) The verb PINNACLE has 2 senses: 1. surmount with a pinnacle