magnate (n.)

mid-15c., "high official, great man, noble, man of wealth," from Late Latin magnates, plural of magnas "great person, nobleman," from Latin magnus "great, large, big" (of size), "abundant" (of quantity), "great, considerable" (of value), "strong, powerful" (of force); of persons, "elder, aged," also, figuratively, "great, mighty, grand, important," from suffixed form of PIE root *meg- "great."