1a comb or tuft of feathers, fur, or skin on the head of a bird or other animal.
a thing resembling a tuft, especially a plume of feathers on a helmet.
2the top of something, especially a mountain or hill:she reached the crest of the hill
the curling foamy top of a wave.
Anatomy a ridge along the surface of a bone.
the upper line of the neck of a horse or other mammal.
3 Heraldry a distinctive device borne above the shield of a coat of arms (originally as worn on a helmet), or separately reproduced, for example on writing paper or silverware, to represent a family or corporate body.
reach the top of (something such as a hill or wave):she crested a hill and saw the valley spread out before her
[no object]US (of a river) rise to its highest level:the river was expected to crest at eight feet above flood stage
[no object] (of a wave) form a curling foamy top.
(be crested) have attached or affixed at the top:his helmet was crested with a fan of spikes
Middle English: from Old French creste, from Latin crista 'tuft, plume'