acardiac
adjective
acar·di·ac
| \ (ˈ)ā-ˈkär-dē-ˌak
\
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Medical Definition of acardiac
: lacking a heart
A normal (pump) twin provides circulation for itself and for an abnormally developing acardiac (perfused) twin. The acardiac twin is not connected to the placenta but, rather, directly to the umbilical cord of the pump twin. — P. Malladi et al., in Pediatric Surgery and Urology: Long Term Outcomes, 2006
also
: marked by the presence of an acardiac fetus
Acardiac pregnancies are extraordinarily rare; nationwide they occur in one out of every 35,000 pregnancies … — Betsy Querna, The Herald News (Passaic County, New Jersey), 11 Sept. 2007