part of ileum lymph node Peyer's gland Any of numerous large oval patches of closely aggregated nodules of lymphoid tissue in the walls of the small intestine especially in the ileum that partially or entirely disappear in advanced life and in typhoid fever become the seat of ulcers which may perforate the intestines. BTO:0001784 BrendaTissueOBO Peyer's patch Peyers gland Peyers patch