pharyngeal tonsil vs third tonsil

pharyngeal tonsil and third tonsil both are nouns.

Word	Noun	Adjective	Verb	Adverb
pharyngeal tonsil	Yes	No	No	No
third tonsil	Yes	No	No	No

As nouns, pharyngeal tonsil and third tonsil are synonyms defined as:

pharyngeal tonsil and third tonsil: a collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx)

Other synonyms of pharyngeal tonsil include adenoid, Luschka's tonsil, tonsilla adenoidea, tonsilla pharyngealis.

pharyngeal tonsil (noun)	third tonsil (noun)
a collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx)	a collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx)