“tonsillolith (also called tonsil stone, tonsillar debris, tonsillar pearl, zot, pebbles, bad breath bead, or calculus of the tonsil) is a piece (or more commonly, a cluster) of calcareous matter which forms in the rear of the mouth, in the crevasses (called tonsillar crypts) of the palatine
tonsils (which are what most people commonly refer to as simply
tonsils).
Protruding tonsilloliths may have the feel of a foreign object, lodged in the back of the tonsil crypt.