intestinal tonsil, one of a group of lymphatic nodules forming a single layer in the mucous membrane of the ileum opposite the mesenteric attachment. The nodules are oval patches about 1 cm wide and extend for about 4 cm along the intestine. In most individuals they appear in the distal ileum, but they also appear in the jejunum of a few individuals. Also called Peyer’s patches. Compare lingual tonsil, palatine tonsil, pharyngeal tonsil.