definition of
peak

[1] #1 peak n. [extremum] the most extreme possible amount or value; "voltage peak". wn

[2] #2 peak n. [flower, prime, heyday, bloom, blossom, efflorescence, flush] the period of greatest prosperity or productivity. wn

[3] #3 peak n. [acme, height, elevation, pinnacle, summit, superlative, meridian, tiptop, top] the highest level or degree attainable; the highest stage of development; "his landscapes were deemed the acme of beauty"; "the artist's gifts are at their acme"; "at the height of her career"; "the peak of perfection"; "summer was at its peak"; "...catap. wn

[4] #4 peak n. [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". wn

[5] #5 peak v. [top out] to reach the highest point; attain maximum intensity, activity; "That wild, speculative spirit peaked in 1929";"Bids for the painting topped out at $50 million". wn