rectum Meaning, Definition & Usage

  1. noun the terminal section of the alimentary canal; from the sigmoid flexure to the anus

WordNet

Rec"tum noun
Etymology
NL. (sc. intestinum), fr. L. rectus straight. See Right.
Definitions
  1. (Anat.) The terminal part of the large intestine; -- so named because supposed by the old anatomists to be straight. See Illust. under Digestive.

Webster 1913