1. Having no placenta
   "monotremes and marsupials are aplacental mammals"

Antonym: placental

• blood blister
• blood brother
• blood brotherhood
• blood cell
• blood clam
• blood clot
• blood clotting
• blood coagulation
• blood corpuscle
• blood count
• blood cup
• blood cyst
• blood disease
• blood disorder
• blood donor
• blood dyscrasia
• blood extravasation
• blood feud
• blood flower
• blood fluke
• blood glucose
• blood group
• blood heat
• blood kinship
• blood knot