HELIOTROPISM Meaning of HELIOTROPISM in English [ ˌhi:lɪə(ʊ)'trəʊpɪz(ə)m ]■ noun Biology growth or movement of a plant or other organism in response to sunlight.Derivativesheliotropic adjective Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004