Merriam-Webster's Collegiate® Dictionary, 11th Edition
CREST
I. noun
Etymology: Middle English creste, from Anglo-French, from Latin crista; probably akin to Latin crinis hair
Date: 14th century
1. a showy tuft or process on the head of an animal and especially a bird, the plume or identifying emblem worn on a knight's helmet, c. a heraldic representation of the crest, a heraldic device depicted above the escutcheon but not upon a helmet, coat of arms 2a, a ridge or prominence on a part of an animal body, something suggesting a crest especially in being an upper prominence, edge, or limit: as, peak , the ridge of a roof, the top of a wave,
3. a high point of an action or process and especially of one that is rhythmic, climax , culmination , crestal adjective crestless adjective
II. verb
Date: 15th century
transitive verb to furnish with a crest, to reach the crest of , intransitive verb to rise to a crest