• enPR: pēk, IPA: /piːk/

From earlier peake, peek, peke, from Middle English pek (in place names), itself an alteration of pike, pyke, pyk ("a sharp point, pike"), from Old English pīc, piic ("a pike, needle, pin, peak, pinnacle"), from Proto-Germanic *pīkaz.

peak (plural peaks)

1. A point; the sharp end or top of anything that terminates in a point; as, the peak, or front, of a cap.
2. The highest value reached by some quantity in a time period.

   Synonyms: apex, pinnacle, Thesaurus:apex

   The stock market reached a peak in September 1929.

3. (geography) The top, or one of the tops, of a hill, mountain or range, ending in a point.

   Synonyms: summit, top

   They reached the peak after 8 hours of climbing.

4. (geography) The whole hill or mountain, especially when isolated.
   • 1898, Arnold Henry Savage Landor, chapter 62, in In the Forbidden Land:

     To the South we observed a large plain some ten miles wide, with snowy peaks rising on the farther side. In front was a hill projecting into the plain, on which stood a mani wall; and this latter discovery made me feel quite confident that I was on the high road to Lhassa.

5. (nautical) The upper aftermost corner of a fore-and-aft sail.

   peak-halyards

   peak-brails

6. (nautical) The narrow part of a vessel's bow, or the hold within it.
7. (nautical) The extremity of an anchor fluke; the bill.
8. (mathematics) A local maximum of a function, e.g. for sine waves, each point at which the value of y is at its maximum.

• French: pic
• Portuguese: ponta
• Russian: ко́нчик

• French: pic, sommet
• German: Höchststand
• Italian: picco
• Portuguese: cume, pico
• Russian: пик
• Spanish: pico

• French: cime, sommet, pic
• German: Gipfel
• Italian: cima
• Portuguese: pico, cume, topo
• Russian: верши́на
• Spanish: cima

• German: Maximum
• Russian: пик

peak (peaks, present participle peaking; simple past and past participle peaked)

1. (transitive, nautical) To raise the point of (a gaff) closer to perpendicular.
2. (transitive, signal processing) To exceed the maximum signal amplitude of (a piece of equipment), resulting in clipping of the signal.
3. (intransitive)
   1. To reach a highest degree or maximum.

      Historians argue about when the Roman Empire began to peak and ultimately decay.

   2. To rise or extend into a peak or point; to form, or appear as, a peak.
      • 1659, T[itus] Livius [i.e., Livy], “(please specify the book number)”, in Philemon Holland, transl., The Romane Historie […], London: […] W. Hunt, for George Sawbridge, […], →OCLC ↗:

        There peaketh up a mightie high mounte.

4. (gender-critical) To cause to adopt gender-critical or trans-exclusionary views (ellipsis of peak trans).

• culminate

• German: kulminieren, gipfeln
• Spanish: culminar

peak

1. At the greatest extent; maximum.

   peak oil, Peak TV

2. (slang) Maximal, quintessential, archetypical; representing the culmination of its type.

   Knowing obscure 19th-century slang is peak nerd.

3. (MLE) Bad.

   Synonyms: Thesaurus:bad

4. (MLE) Unlucky; unfortunate.

   Synonyms: Thesaurus:unlucky

   You didn't get a spot? That's peak.

5. (internet slang) Very good or high-quality.

   That movie last night was peak!

peak (peaks, present participle peaking; simple past and past participle peaked)

1. (intransitive) To become sick or wan.
2. (intransitive) To acquire sharpness of figure or features; hence, to look thin or sickly.
   • c. 1606 (date written), William Shakespeare, “The Tragedie of Macbeth”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act I, scene iii]:

     Dwindle, peak, and pine.

3. (intransitive) To pry; to peep slyly.

• peaky

peak (uncountable)

1. Alternative form of peag.

peak (peaks, present participle peaking; simple past and past participle peaked)

1. Surname.