a person of great influence, importance, or standing in a particular enterprise, field of business, etc.: a railroad magnate.
2.
a person of eminence or distinction in any field: literary magnates.
3.
a member of the former upper house in either the Polish or Hungarian parliament.
Origin: 1400–50; back formation from Middle English magnates (plural) < Late Latin magnātēs leading people, equivalent to Latin magn(us) magn- + -ātēs, plural of -ās noun suffix
1430, "great man, noble, man of wealth," from L.L. magnates, pl. of magnas (gen. magnatis) "great person, nobleman," from L. magnus "great," from PIE *mag-no-, from base *meg- "great" (cf. Skt. maha-, mahat- "great," Gk. megas, fem. megale "great, large," Goth. mikils, O.E. micel "great, big, many").