Source : WordNet®

third tonsil
     n : 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}, {tonsilla pharyngealis}, {tonsilla
         adenoidea}]