The term "third tonsil" typically refers to the lingual tonsil located at the back of the tongue. Other synonyms for this structure include the base of the tongue, the tonsilla lingualis, and the adenoid of the tongue. The lingual tonsil is made up of lymphatic tissue and helps to protect the body against infection. It can become inflamed or enlarged, causing symptoms such as sore throat, difficulty swallowing, and bad breath. Treatment options for lingual tonsil issues may include antibiotics, warm salt water gargles, or surgical removal in severe cases. It is always important to consult a healthcare professional for proper diagnosis and treatment of any medical condition.