superimpregnation
/ˌsuːpərˌɪmprɛɡˈneɪʃn/ /ˌsjuːpərˌɪmprɛɡˈneɪʃn/Now rare
noun
Physiology. Superfetation or superfecundation; an instance of this. Now historical and rare.
Origin
Late 17th century (in an earlier sense). From super- + impregnation. In sense 1 after superimpregnate.