The story
- Proto-Indo-European · derived from*-kos, *-ḱos
- Latin · derived from-icus
- Old French · derived from-ique
- Middle English · inherited from-ik
- English today-ic
From Middle English -ik, from Old French -ique, from Latin -icus, from Proto-Indo-European *-kos, *-ḱos, formed with the i-stem suffix *-i- and the adjectival suffix *-kos, *-ḱos. Compare Ancient Greek -ικός (-ikós), Sanskrit -इक (-ika) and Old Church Slavonic -ъкъ (-ŭkŭ). Doublet of -y; compare also -ac. Proto-Indo-European *-kos on noun stems carried the meaning 'characteristic of, like, typical, pertaining to', and on adjectival stems it acted emphatically.
Etymology from Wiktionary, CC BY-SA 4.0.