physeteridæ

from The Century Dictionary.

• noun A family of existent delphinoid Cetacea, of the group Delphinoidea, having functional teeth in the lower jaw only, and the skull strongly asymmetrical.
• noun In stricter use, a family of sperm-whales, typified by the genus Physeter, and containing the subfamilies Physeterinæ and Kogiinæ, or ordinary and pygmy sperm-whales.