The Collaborative International Dictionary of English v.0.48:

Tonsil \Ton"sil\, n. [L. tonsill?, pl.: cf. F. tonsille. ]
   (Anat.)
   One of the two glandular organs situated in the throat at the
   sides of the fauces. The tonsils are sometimes called the
   almonds, from their shape.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tonsil
    n 1: either of two masses of lymphatic tissue one on each side
         of the oral pharynx [syn: tonsil, palatine tonsil,
         faucial tonsil, tonsilla]