APEX Definition

APEX
abbreviation

1. Advance Purchase Excursion, a reduced fare that is available on some air and train tickets when they are booked a certain period in advance.
(Brit)
2. Association of Professional, Executive, Clerical and Computer Staff.

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apex
noun apexes, apices

1. The highest point or tip.

Thesaurus: top, pinnacle, zenith, peak, summit, vertex, high point, crest, apogee.
2. geom.
The highest point of a plane or solid figure relative to some line or plane.
Thesaurus: top, pinnacle, zenith, peak, summit, climax, crowning point, high point, crest, culmination, apogee, acme; Antonym: nadir, bottom.
3. A climax or pinnacle. See also apical.

Etymology: 17c: Latin, meaning ‘peak'.