14 letters · 28 points in Scrabble
verb make (an organism or substance) sensitive to the influence of radiant energy and especially light
originEtymology 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- English sensitize English photosensitize From photo- + sensitize.
Etymology from Wiktionary, CC BY-SA 3.0