盲 (blind) +
肠 (intestine) = 'blind gut' — a literal calque of the Latin caecum ('blind'), referring to the closed-end pouch where the small intestine joins the large. In strict anatomy
盲肠 is the cecum and
阑尾 (lánwěi) is the appendix proper, but in everyday Chinese
盲肠炎 is used loosely for what English calls 'appendicitis.'
