[syn: venous sinus, sinus]
The Collaborative International Dictionary of English v.0.48:
Sinus \Si"nus\, n.; pl. L. Sinus, E. Sinuses. [L., a bent
surface, a curve, the folds or bosom of a garment, etc., a
bay. Cf. Sine, n.]
1. An opening; a hollow; a bending.
2. A bay of the sea; a recess in the shore.
3. (Anat. & Zool.) A cavity; a depression. Specifically:
(a) A cavity in a bone or other part, either closed or
with a narrow opening.
(b) A dilated vessel or canal.
4. (Med.) A narrow, elongated cavity, in which pus is
collected; an elongated abscess with only a small orifice.
5. (Bot.) A depression between adjoining lobes.
Note: A sinus may be rounded, as in the leaf of the white
oak, or acute, as in that of the red maple.
Pallial sinus. (Zool.) See under Pallial.
Sinus venosus. [L., venous dilatation.] (Anat.)
(a) The main part of the cavity of the right auricle of
the heart in the higher vertebrates.
(b) In the lower vertebrates, a distinct chamber of the
heart formed by the union of the large systematic
veins and opening into the auricle.
WordNet (r) 3.0 (2006):
n 1: an abnormal passage leading from a suppurating cavity to
the body surface [syn: fistula, sinus]
2: any of various air-filled cavities especially in the bones of
3: a wide channel containing blood; does not have the coating of
an ordinary blood vessel [syn: venous sinus, sinus]
Moby Thesaurus II by Grady Ward, 1.0:
48 Moby Thesaurus words for "sinus":
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