paratrophic
/ˌparəˈtrɒfɪk/ /ˌparəˈtrəʊfɪk/Medicine and Biology. Now rare
adjective
Dependent upon living organic material for nutrition; obligately parasitic. Now rare.
Origin
Mid 19th century (in an earlier sense). From para- + -trophic. In sense 1, after paratrophy.