appendix
n. countable B2 Upper Intermediate US //əˈpɛndɪks// UK //ɐpˈɛndɪks// ap·pen·dix
n. a small tube attached to the large intestine. You use this word when talking about this specific part of the body, especially if it becomes inflamed.
n. a small, finger-shaped pouch attached to the beginning of the large intestine. In medical contexts, it is the site of appendicitis.
The doctor removed his appendix during surgery.
Although the appendix was once thought to be a useless evolutionary remnant, recent research suggests it may serve as a safe house for beneficial gut bacteria.
Borrowed from Latin appendix.