noun

1. any process or growth on the head of an animal, as a comb or feathered tuft on certain birds
2. a plume or emblem, formerly worn on a helmet
3. a helmet or its apex
4. a heraldic device placed above the shield in a coat of arms, or used separately on seals, silverware, note paper, etc.
5. the top of anything, or the line or surface along the top; summit; ridge the crest of a wave, a mountain crest
6. the highest point, level, degree, etc.
7. 1. the ridge of the neck of a horse, lion, etc.
   2. the mane growing on this
8. cresting
9. a projecting ridge, as along a bone

Etymology: ME creste < OFr < L crista, prob. < IE base *(s)kreis-, to shake > MIr cressaim, I shake, ON hrista, to shake

transitive verb

1. to provide or decorate with a crest
2. to lie at the top of; crown
3. to reach the crest of

intransitive verb

1. to form a crest, as a wave
2. to reach its highest level the flooding river crested at 30 feet