Probably from sun; common, i.e. (literally) shared by all or several, or (ceremonially) profane -- common, defiled, unclean, unholy.

see GREEK sun

κοινά (koina) − 2 Occurrences

κοιναῖς (koinais) − 2 Occurrences

κοινὴν (koinēn) − 1 Occurrence

κοινῆς (koinēs) − 1 Occurrence

κοινὸν (koinon) − 8 Occurrences