apex

noun

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

   “the apex of the building”

2. geometryThe highest point in a plane or solid figure, relative to a base line or plane.

3. chiefly anatomyThe pointed fine end of something.

4. The lowest part of the human heart.

5. The deepest part of a tooth's root.

6. botanyThe end of a leaf, petal or similar organ opposed to the end where it is attached to its support.

7. botanyThe growing point of a shoot.

8. astronomyThe point on the celestial sphere toward which the Sun appears to move relative to nearby stars.

9. physicsThe lowest point on a pendant drop of a liquid.

10. miningUSThe end or edge of a vein nearest the surface.

11. typography: A diacritic in Classical Latin that resembles and gave rise to the acute.

12. typography: A diacritic in Middle Vietnamese that indicates /ŋ͡m/.

13. typography: 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".

14. figurativelyThe moment of greatest success, expansion, etc.

    “the apex of civilization”