1. (noun)crest the top line of a hill, mountain, or wave
2. (noun)peak, crown, crest, top, tip, summit the top or extreme point of something (usually a mountain or hill)
"the view from the peak was magnificent"; "they clambered to the tip of Monadnock"; "the region is a few molecules wide at the summit"
3. (noun)crown, crest the center of a cambered road
4. (noun)crest (heraldry) in medieval times, an emblem used to decorate a helmet
5. (noun)crest a showy growth of e.g. feathers or skin on the head of a bird or other animal
6. (verb)cap, crest lie at the top of
"Snow capped the mountains"
7. (verb)crest reach a high point
"The river crested last night"