Source : Webster's Revised Unabridged Dictionary (1913)

Hypogene \Hyp"o*gene\, a. [Pref. hypo- + the root of Gr. ? to be
   born: cf. F. hypog[`e]ne.] (Geol.)
   Formed or crystallized at depths the earth's surface; -- said
   of granite, gneiss, and other rocks, whose crystallization is
   believed of have taken place beneath a great thickness of
   overlying rocks. Opposed to epigene.