gastromelus

gas·trom·e·lus

(gas-trom'ĕ-lŭs),
A condition in which an individual has a supernumerary limb attached to the abdomen. See: conjoined twins.
[gastro- + G. melos, a limb]

gastromelus

An unequal conjoined twin in which the parasitic twin largely consists of a limb attached to the abdominal wall of the host twin; it is little used in the working medical parlance.