apex

Borrowed from Latin apex (“point, tip, summit”).

• IPA^(key): /ˈeɪ.pɛks/

• Audio (Southern England):

  (file)

• Rhymes: -eɪpɛks

apex (plural apices or apexes)

1. The highest or the greatest part of something, especially forming a point.

   Synonyms: peak, top, summit, vertex

   the apex of the building

   1. (geometry) The highest point in a plane or solid figure, relative to a base line or plane.
   2. (chiefly anatomy) The pointed fine end of something.

      Synonyms: end, tip

      1. The lowest part of the human heart.
         • 1951 March, J. H. Lehmann, A. D. Johnson, W. C. Bridges, J. Michel, D. M. Green, “Cardiac Catheterization—A Diagnostic Aid in Congenital Heart Disease”, in Northwest Medicine, volume 50, number 3, Portland, Ore.: Northwest Medical Publishing Association, page 175:

           B.P. 118/68. Grade I diastolic murmur best heard over apex. Patient well and had no complaints referable to heart. Origin of the diastolic murmur is open to conjecture.

      3. The deepest part of a tooth's root.
   3. (botany) The end of a leaf, petal or similar organ opposed to the end where it is attached to its support.

      Synonym: tip

   4. (botany) The growing point of a shoot.
   5. (astronomy) The point on the celestial sphere toward which the Sun appears to move relative to nearby stars.

      Hyponym: solar apex

   6. (physics) The lowest point on a pendant drop of a liquid.
   7. (mining, US) The end or edge of a vein nearest the surface.
   8. (typography):
      1. A diacritic in Classical Latin that resembles and gave rise to the acute.
      2. A diacritic in Middle Vietnamese that indicates /ŋ͡m/.
      3. A sharp upward point formed by two strokes that meet at an acute angle, as in "W", uppercase "A", and closed-top "4", or by a tapered stroke, as in lowercase "t".

         Coordinate term: vertex

   9. (motor racing) The part of a corner where the racing line is nearest the inside of the bend.
2. An obstacle for a horse to jump over, consisting of a triangular corner fence.
3. (figuratively) The moment of greatest success, expansion, etc.

   Synonyms: acme, culmination, height, peak, pinnacle

   the apex of civilization

   • 2002, Jeffrey Rowland, “Day 2 (The Slagathors)”, in Wigu Adventures‎^[1], page 58:

     It would be an intense disgust. The absolute apex of teen angst.

   • 2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, →ISBN, →OCLC, PC, scene: Virmire:

     The pattern has repeated itself more times than you can fathom. Organic civilizations rise, evolve, advance. And at the apex of their glory, they are extinguished.

4. (attributive, ecology) The top of the food chain.
5. A conical priest cap.

• See also Thesaurus:apex

• apical

• “apex”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “apex”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “apex”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.
• “apex”, in OneLook Dictionary Search.

From Proto-Italic *apeks, from Proto-Indo-European *h₂ep- (“to join, fit”). De Vaan approches this connection with caution since a link with apiō is through some meanings feasible in addition to the observation that most ex, -icis are technical terms without Indo-European origin.^[1]

• (Classical Latin) IPA^(key): [ˈa.pɛks]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈaː.peks]

apex m (genitive apicis); third declension

1. The extreme end of a thing; the point, summit, top.

   Synonyms: cacūmen, summa, fastīgium, culmen, vertex, summitās

   Antonym: fundus

2. (literally) The small rod (generally of olive wood) at the top of the flamen's cap, wound around with a woolen cord or "thread".
3. (transferred sense):
   1. The conical leathern cap of an ancient Roman priest (the Flamen), ornamented with this rod.
   2. Any hat or helmet; a crown.
   3. (literally) A projecting point or summit.
      1. (figurative) The highest ornament or honor; the crown of a thing.
   4. (grammar) The macron (long mark over a vowel).
      1. The forms or outlines of the letters.
   5. A letter or any other writing.
   6. (Ecclesiastical Latin, figurative) (of the point or of a Hebrew letter) The least particle, tittle.

Third-declension noun.

• “apex”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “apex”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• "apex", in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• apex in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• “apex”, in Harry Thurston Peck, editor (1898), Harper’s Dictionary of Classical Antiquities, New York: Harper & Brothers
• “apex”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin

Borrowed from Latin apex.

• IPA^(key): /ˈa.peks/

apex n (plural apexuri)

1. (geometry) apex
2. (astronomy) apex

• “apex”, in DEX online—Dicționare ale limbii române (Dictionaries of the Romanian language) (in Romanian), 2004–2025