photoactivity

Etymology tree
Proto-Indo-European *bʰeh₂-
Proto-Indo-European *bʰéh₂os
Proto-Hellenic *pʰáwos
Ancient Greek φᾰ́ος (phắos)
Ancient Greek φῶς (phôs)
Ancient Greek φωτο- (phōto-)der.
English photo-
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
Proto-Indo-European *-teh₂
Proto-Indo-European *-ts
Proto-Indo-European *-teh₂ts
Proto-Italic *-tāts
Latin -tās
Latin āctīvitāsder.
Middle French activitébor.
English activity
English photoactivity
From photo- + activity.