-ic

from The Collaborative International Dictionary of English v.0.48

-ic \-ic\ [L. -icus, Gr. ?: cf. F. -ique.]
   1. A suffix signifying, in general, relating to, or
      characteristic of; as, historic, hygienic, telegraphic,
      etc.
      [1913 Webster]

   2. (Chem.) A suffix, denoting that the element indicated
      enters into certain compounds with its highest valence, or
      with a valence relatively higher than in compounds where
      the name of the element ends in -ous; as, ferric,
      sulphuric. It is also used in the general sense of
      pertaining to; as, hydric, sodic, calcic.
      [1913 Webster]