from the GNU version of the Collaborative International Dictionary of English
- n.pl. The group that includes all ordinary or placental mammals; the Placentalia. See mammalia.
from The Century Dictionary and Cyclopedia
- n. The highest of three primary divisions of mammals, or subclasses of the class Mammalia (the other two being Didelphia and Ornithodelphia); placental mammals, or Placentalia.
Sorry, no etymologies found.