subatomic

/ˈsʌbəˌtɑmɪk/

Definitions of subatomic

1. adjective

   of or relating to constituents of the atom or forces within the atom
   “subatomic particles”

   “harnessing subatomic energy”
2. adjective

   of smaller than atomic dimensions
   synonyms:

   little, small

   limited or below average in number or quantity or magnitude or extent