Omega /(ō*mē"gȧ [or] ō*mā"gȧ [or] ō"mē̇*gȧ; 277)/

O·me·ga

Omega

n.
  1. The last letter of the Greek alphabet. See Alpha.
  2. The last; the end; hence, death.
    Omega! thou art Lord,” they said.
    The alpha and omega of science.
    — Sir J. Herschel.

Phrases & Compounds

Alpha and Omega
the beginning and the ending; hence, the chief, the whole.