mega-

aff.

a combining form meaning “extremely large, huge,” orig. a variant of megalo- (megalith), used also in the names of units of measure equal to one million of a given base unit (megahertz; megaton), and by extension, now freely used to form words denoting very large quantities (megabucks), large things (megastructure) or, more generally, things that are extraordinary examples of their kind (megahit; megatrend). Abbr.: M I, 7) Also, esp. before a vowel, meg-. Etymology: comb. form repr. Gk mégas large