ˈtagmə noun
( plural tagma·ta -məd.ə)
Etymology: New Latin, from Greek tagma arrangement, order, row, from tassein, tattein to arrange — more at tactics
: a compound body section of an arthropod resulting from embryonic fusion of two or more somites (as the cephalothorax of a spider) or consisting of two or more distinguishable segments (as the thorax of an insect)