Medical Definition of crest
1: a showy tuft or process on the head of an animal and especially a bird
2: a process or prominence on a part of an animal body: asa: the upper curve or ridge of the neck of a quadruped (as a horse); also : the mane borne on such a crestb: a ridge especially on a bone <the crest of the tibia>—see frontal crest, occipital crest
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