'third tonsil' definitions:

A collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx); "hypertrophy of the pharyngeal tonsils is called adenoids"; "enlarged adenoids may restrict the breathing of children" [syn: pharyngeal tonsil, adenoid, Luschka's tonsil, third tonsil, tonsilla pharyngealis, tonsilla adenoidea]