photoconsumptive

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 *ḱe?
Proto-Indo-European *ḱóm
Proto-Italic *kom
Proto-Italic *kom-
Latin con-
Proto-Indo-European *upó
Proto-Italic *supo
Latin sub
Latin sub-
Proto-Indo-European *h₁em-der.
Proto-Italic *emō
Latin emō
Latin sūmō
Latin cōnsūmō
Latin cōnsūmptus
Proto-Indo-European *-wós
Proto-Indo-European *-iHwósder.
Latin -īvus
Old French -ifbor.
Middle English -ive
Middle English consumptive
English consumptive
English photoconsumptive
From photo- + consumptive.