Source : Webster's Revised Unabridged Dictionary (1913)

Coarctate \Co*arc"tate\, a. [L. coarctatus, p. p. of coarctare
   to press together; co- + arctare to press together, from
   arctus, p. p. See {Arctation}.] (Zo["o]l.)
   Pressed together; closely connected; -- applied to insects
   having the abdomen separated from the thorax only by a
   constriction.

   {Coarctate pupa} (Zo["o]l.), a pupa closely covered by the
      old larval skin, as in most Diptera.