(n.) An architectural member, upright, and generally ending in a small spire, -- used to finish a buttress, to constitute a part in a proportion, as where pinnacles flank a gable or spire, and the like. Pinnacles may be considered primarily as added weight, where it is necessary to resist the thrust of an arch, etc.
PINNACLE
Meaning of PINNACLE in English
Webster's English dictionary. Английский словарь Webster. 2012