Sinus

Noun

 * 1)  A pouch or cavity in any organ or tissue, especially the paranasal sinus.
 * 2)  An abnormal cavity or passage such as a fistula, caused by the destruction of tissue.

Derived terms

 * sinusitis
 * ethmoid sinus
 * frontal sinus
 * maxillary sinus
 * sphenoid sinus
 * paranasal sinus

Thesaurus
alveolation, alveolus, antrum, arc, armpit, basin, bow, bowl, catacaustic, catenary, caustic, cavity, circle, concave, concavity, conchoid, crater, crook, crypt, cup, curl, curve, depression, diacaustic, dip, ellipse, festoon, fold, follicle, funnel chest, hole, hollow, hollow shell, hook, hyperbola, lacuna, lituus, parabola, pit, pocket, punch bowl, scoop, shell, sink, socket, tracery, trough, vug