eventognathi

from The Century Dictionary.

• A large suborder of fresh-water physostomous fishes, of most parts of the world: so called on account of the peculiar development of the lower pharyngeal bones.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) An order of fishes including a vast number of freshwater species such as the carp, loach, chub, etc.