thallophyte Syllabification: (thal·lo·phyte)Pronunciation: /ˈTHaləˌfīt/Definition of thallophyte noun Botany a plant that consists of a thallus. Derivatives thallophytic adjective Origin: mid 19th century: from modern Latin Thallophyta (former taxon), from Greek thallos (see thallus) + -phytethallophyte in other Oxford dictionaries Definition of thallophyte in the British & World English dictionary