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Synonyms

apex

1 American  
[ey-peks] / ˈeɪ pɛks /

noun

plural

apexes, apices

  1. the tip, point, or vertex; summit.

  2. climax; peak; acme.

    His election to the presidency was the apex of his career.

  3. Astronomy. solar apex.

APEX 2 American  
[ey-peks] / ˈeɪ pɛks /

noun

  1. a type of international airfare offering reduced rates for extended stays that are booked in advance.

apex 1 British  
/ ˈeɪpɛks /

noun

  1. the highest point; vertex

  2. the pointed end or tip of something

  3. a pinnacle or high point, as of a career, etc

  4. Also called: solar apex.  astronomy the point on the celestial sphere, lying in the constellation Hercules, towards which the sun appears to move at a velocity of 20 kilometres per second relative to the nearest stars

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
APEX 2 British  
/ ˈeɪpɛks /

acronym

  1. Advance Purchase Excursion: a reduced airline or long-distance rail fare that must be paid a specified number of days in advance

  2. (in Britain) Association of Professional, Executive, Clerical, and Computer Staff

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of apex1

Borrowed into English from Latin around 1595–1605

Origin of APEX2

First recorded in 1970–75; A(dvance) P(urchase) Ex(cursion)

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The findings suggest that peaceful coexistence between these two apex predators depends less on the total amount of prey available and more on having a variety of prey species and access to safe escape terrain.

From Science Daily • Mar. 3, 2026

A wolf arrived in Los Angeles County on Saturday morning, marking the first time the apex predator has been documented in the area in at least a century, according to state wildlife officials.

From Los Angeles Times • Feb. 7, 2026

He says not all zoos will survive but describes the birth of a critically-endangered Amur leopard at Dartmoor Zoo - a species on the brink of extinction - as "the apex of our achievement".

From BBC • Feb. 2, 2026

They also found many arthropods -- a family that includes modern-day crabs and insects -- including spiny, stalk-eyed creatures called radiodonts which were the apex predator of the time.

From Barron's • Jan. 28, 2026

Gritting his teeth, he made it to the apex of the arch.

From "Redwall" by Brian Jacques

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.