-IC

a suffix signifying, in general, relating to, or characteristic of; as, historic, hygienic, telegraphic, ·etc.

2. -ic ·- 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.