-acea Also -acean.
Groups of animals.
[The neuter plural of the Latin ending -aceus, belonging to, or of the nature of.]
Terms in -acea are systematic names of animal groups, mostly orders but also classes and a few superfamilies. Examples include Crustacea, a class of mostly marine arthropods that includes lobsters, shrimps, crabs, and barnacles; Cetacea, the order that includes the whales, dolphins, and porpoises; and Cumacea (Greek kuma, billow or wave), the order containing the tadpole shrimps.
Names in -acean either indicate individual members of these groups or adjectives relating to them. The most common examples are cetacean and crustacean; another is larvacean for a member of the Larvacea, a class of minute transparent planktonic animals related to the sea squirts. See also -ae and -ean.