tagma

tagma (noun; plural tagmata; Greek tagma, an arrangement): 1. A major division of body regions of a metamerically segmented animal, particularly arthropods

See also: pseudotagma. 2. (Arthropoda: Chelicerata) The prosoma and opisthosoma. 3. (Arthropoda: Insecta) The head, thorax, pedicel and gaster of Formicidae.