What is the meaning of crest?

noun

• The top line of a hill, mountain, or wave.
• The top or extreme point of something (usually a mountain or hill. )
  • usage: "the view from the peak was magnificent"; "they clambered to the tip of Monadnock"; "the region is a few molecules wide at the summit"
  • synonyms: peak, crown, top, tip, summit
• The center of a cambered road.
  • synonyms: crown
• Heraldry) in medieval times, an emblem used to decorate a helmet. (
• A showy growth of e. G. Feathers or skin on the head of a bird or other animal.

verb

• Lie at the top of.
  • usage: "Snow capped the mountains"
  • synonyms: cap
• Reach a high point.
  • usage: "The river crested last night"