duplicitas
du·plic·i·tas
(dū-plis'i-tăs),duplicitas
(1) The doubling of a body part.(2) An obsolete term for conjoined twins, see there (popularly known as Siamese twins).
The obsolete term duplicitas is defined as the apparent doubling of body segments; the root -pagus is preferred, which carries a prefix according to attached region—as in craniopagus, thoracopagus and pygopagus (for conjoined twins who are joined at the head, chest and hips, respectively).