c g s

from The Collaborative International Dictionary of English v.0.48

C G S \C. G. S.\
   An abbreviation for {Centimeter}, {Gram}, {Second}. --
   applied to a system of units much employed in physical
   science, based upon the centimeter as the unit of length, the
   gram as the unit of weight or mass, and the second as the
   unit of time.
   [1913 Webster]