Updated March 01, 2015.

Definition: The adenoids are glands that work as part of the lymphatic system, one of the infection fighting portions of the immune system. The adenoids are one of three sets of tonsils in the back of the mouth.

In the course of fighting infection, they may become infected themselves. If the infection happens repeatedly, they may need to be removed in a surgery called an adenoidectomy, which is often done along with a tonsillectomy.

Also Known As: adenoid, adenoids, tonsils

Common Misspellings: adnoids, adnoid, adnoyd, adenoyd

Examples: Because the adenoids were infected, they were removed along with the other tonsils during surgery.