Crest (hydrology) definition

(1) A showy growth of e.g. feathers or skin on the head of a bird or other animal

(2) (heraldry) in medieval times, an emblem used to decorate a helmet

(3) The center of a cambered road

(4) The top line of a hill, mountain, or wave

(5) The top point of a mountain or hill

"The view from the peak was magnificent"

"They clambered to the summit of Monadnock"

(6) Reach a high point

"The river crested last night"

(7) Lie at the top of

"Snow capped the mountains"