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

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.