| n. pl. | 1. | (Zool.) One of the subclasses of Crustacea, including a large number of species, many of them minute. The group embraces several orders; as the |
| Noun | 1. | Entomostraca - in some older classifications includes the Branchiopoda and Copepoda and Ostracoda and Cirripedia; no longer in technical use Synonyms: subclass Entomostraca |