apex

Etymology

It is borrowed from Latin apex (“summit, peak, tip, top, extreme end”).^{[2][3][4][5][6]} In Latin the word also meant the small rod or spike at the top of the cap worn by a flamen, and a helmet's top, a bird's crest, the tip of a stamen and the mark written over a long vowel; in post-classical Latin it also meant "highest point, acme", in Tertullian in the early 3rd century.^[2][7] It is perhaps formed from apiō (“to fasten, attach”),^[2][4][7][8] as vertex comes from vertō (“to turn”),^[2][7] so that it first meant something fastened to the top.^[7][3] Merriam-Webster likewise takes it as probably akin to aptus (“fastened, attached”), the source of apt,^[9] and Etymonline traces it through this verb to Proto-Indo-European *ap- (“to take, reach”), noting that if the first idea was "point" rather than "top" the word may have another origin.^[3]

Earliest recorded meaning

The small rod wrapped with woollen thread on the cap of a Roman priest: 1578, in a translation of Appian.^[2] The general sense "tip, top, peak" follows in 1590.^[2]

Semantic evolution

Most dictionaries date the English word to about 1600: Barnhart and Merriam-Webster to 1601, Etymonline to about 1600, and the Shorter Oxford to the early 17th century,^[4][9][3][5] while “Word Origins” puts it in the late 16th century;^[10] the revised OED (2016) has the Roman sense from 1578.^[2] From the sense "pointed top" the word spread into the sciences: in geometry, the vertex of a triangle, cone or pyramid (1659); in anatomy, the narrow end of the heart (1682), after post-classical Latin apex cordis; and in astronomy, the point in the sky towards which the solar system is moving (1783, in W. Herschel).^[2] The figurative sense "highest point, culmination" is recorded from 1624, and "the top of a hierarchy" from 1792.^[2] After the Vulgate's rendering of Matthew 5:18, where English Bibles have tittle, apex was also used from 1625 to 1767 for the smallest part of anything written, a jot.^[2] Johnson (1755) defined it simply as "the tip or point of any thing".^[11] The verb followed in the 19th century: to give a pointed top to (1834), in American mining of a lode reaching its highest point (1886), to reach a peak (1895), and in motor racing to take a corner at its apex (1988).^[2][9]

Timeline

• 1578 – the rod on the cap of a Roman priest.^[2]
• 1590 – the highest part or pointed tip of something.^[2]
• 1601 – first record according to Barnhart and Merriam-Webster.^[4][9]
• 1624 – figurative, the highest point, the climax.^[2]
• 1659 – geometry, the vertex of a figure.^[2]
• 1682 – anatomy, the narrow end of the heart.^[2]
• 1783 – astronomy, the solar apex.^[2]
• 1792 – the top of a hierarchy.^[2]
• 1834 – verb, to give a pointed top to.^[2]
• 1835 – botany, the tip of a shoot or root.^[2]
• 1971 – APEX, an acronym for a reduced airline fare.^[2][9]

Modern meaning

Noun

1. The highest point of something; the summit, top or peak: the apex of the roof.
2. The pointed end or tip of something.
3. The high point of a career, process or the like; the pinnacle or culmination.
4. (geometry) The vertex of a triangle, cone or pyramid.
5. (anatomy) The narrow end of the heart.
6. (botany) The tip of a growing shoot or root.
7. (astronomy) The solar apex, the point in the sky, in the constellation Hercules, towards which the Sun appears to move.

Verb

1. To reach a peak or high point; to culminate.
2. (mining) Of a vein of ore, to reach its highest point near the surface.
3. (motor racing) To take a corner at its apex.

Word family

• antapex

Related words

• apical
• apt

Usage notes

The plural is apexes or the Latin apices;^[12][9] Etymonline calls apices the proper plural.^[3] APEX, from the initials of Advance Purchase Excursion, is a reduced airline or rail fare booked in advance (1971), and was also the name of a British trade union (1972); the OED thinks both acronyms probably play on apex.^[2][12][6]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
7. ^ a b c d Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
9. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
10. ^ Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
11. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins