adrectal,a.Zool.|æˈdrɛktəl| [f. ad- + rectal a.] Situated at or near the rectum; spec. of or pertaining to the purpuriparous glands of certain molluscs. 1883Encycl.Brit. XVI. 648/2 The presence of glandular plication of the surface of the mantle-flap..and an adrectal gland (purple-gland).