Ā′pex, n.

noun

n.; pl. Eng. Ā′PĔX-ĔS; Lat. ĀP′Ĭ-CĒS.

  1. The tip, point, or summit of any thing; specifically, (a.) The cap of an ancient flamen or priest. (b.) The crest of an ancient helmet.
  2. The mark of a long syllable.