inactively

Etymology tree
Proto-Indo-European *né
Proto-Indo-European *n̥-
Proto-Italic *n̥-
Latin in-
Proto-Indo-European *h₂eǵ-
Proto-Indo-European *-eti
Proto-Indo-European *h₂éǵeti
Proto-Italic *agō
Latin agō
Proto-Indo-European *-wós
Proto-Indo-European *-iHwósder.
Latin -īvus
▲
Ancient Greek ἐνεργητῐκός (energētĭkós)sl.
Latin āctīvus
Latin ināctīvuslbor.
French inactifder.
English inactive
Proto-Indo-European *leyg-der.
Proto-Germanic *līkąder.
Proto-Germanic *-līkaz
Proto-Germanic *-ê
Proto-Germanic *-līkê
Proto-West Germanic *-līkē
Old English -līċe
Middle English -ly
English -ly
English inactively
From inactive + -ly.