Definition from Wiktionary, the free dictionary
adenoid (not comparable)
adenoid (plural adenoids)
- (anatomy) One of two folds of lymphatic tissue covered by ciliated epithelium. They are found in the roof and posterior wall of the nasopharynx at the back of the throat behind the uvula. They may obstruct normal breathing and make speech difficult when swollen, a condition often called adenitis.
Coordinate terms 
Derived terms 
folds of lymphatic tissue covered by ciliated epithelium