photoperiod Syllabification: (pho·to·pe·ri·od)Pronunciation: /ˈfōtōˌpi(ə)rēəd/Definition of photoperiod noun Botany & Zoology the period of time each day during which an organism receives illumination; day length. Derivatives photoperiodicPronunciation: /ˌfōtōˌpi(ə)rēˈädik/ adjective photoperiod in other Oxford dictionaries Definition of photoperiod in the British & World English dictionary
