A grossly malformed foetus with three heads, joined at the occiput, and a single body. ... Origin: tri-+ G. Inion, nape of the neck, + didymos, twin ... (05 Mar 2000) ... 
Type: Term Pronunciation: trī-in′ē-od′i-mŭs Definitions: 1. A grossly malformed fetus with three heads, joined at the occiput, and a single body.
triiniodymus A grossly malformed fetus with three heads, joined at the occiput, and a single body.