-icsuff.1. Of, relating to, or characterized by: seismic.2. Having a valence higher than that of a specified element in compounds or ions named with adjectives ending in -ous: sulfuric acid.3. One relating to or characterized by: academic.[Middle English, from Old French -ique, from Latin -icus and from Greek -ikos.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.-ic suffix forming adjectives 1. of, relating to, or resembling: allergic; Germanic; periodic. See also -ical 2. (Elements & Compounds) (in chemistry) indicating that an element is chemically combined in the higher of two possible valence states: ferric; stannic. Compare -ous2 [from Latin -icus or Greek -ikos; -ic also occurs in nouns that represent a substantive use of adjectives (magic) and in nouns borrowed directly from Latin or Greek (critic, music)]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014-ic 1. a suffix forming adjectives from other parts of speech, occurring orig. in Greek and Latin loanwords (metallic; poetic; archaic; public) and, on this model, used as an adjective-forming suffix with the particular senses ?having some characteristics of? (opposed to the simple attributive use of the base noun) (balletic; sophomoric); ?in the style of? (Byronic; Miltonic); ?pertaining to a family of peoples or languages? (Finnic; Semitic; Turkic). 2. a suffix, specialized in opposition to -ous, used to show the higher of two valences: ferric chloride. 3. a noun suffix occurring in loanwords from Greek, where such words were orig. adjectival (critic; magic; music). [Middle English -ic, -ik