Sinus

• POS: Noun
• HYPHEN: si=nus

CIDE DICTIONARY

Sinus, n. [L., a bent surface, a curve, the folds or bosom of a garment, etc., a bay. Cf. Sine, n.].

•  An opening; a hollow; a bending.  [1913 Webster]
•  A bay of the sea; a recess in the shore.  [1913 Webster]
•  A cavity; a depression.  [1913 Webster]
•  A narrow, elongated cavity, in which pus is collected; an elongated abscess with only a small orifice.  [1913 Webster]
•  A depression between adjoining lobes.  [1913 Webster]

  " A sinus may be rounded, as in the leaf of the white oak, or acute, as in that of the red maple."  [1913 Webster]

Pallial sinus. (Zoöl.) 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.

OXFORD DICTIONARY

Sinus, n.
1 a cavity of bone or tissue, esp. in the skull connecting with the nostrils.
2 Med. a fistula esp. to a deep abscess.
3 Bot. the curve between the lobes of a leaf.

Etymology

L, = bosom, recess

THESAURUS

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

ROGET THESAURUS

Sinus

Concavity

N concavity, depression, dip, hollow, hollowness, indentation, intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus, lacuna, excavation, strip mine, trough, honeycomb, cup, basin, crater, punch bowl, cell, socket, valley, vale, dale, dell, dingle, combe, bottom, slade, strath, glade, grove, glen, cave, cavern, cove, grot, grotto, alcove, cul-de- sac, gully, arch, bay, excavator, sapper, miner, honeycomb (sponge), depressed, alveolate, calathiform, cup-shaped, dishing, favaginous, faveolate, favose, scyphiform, scyphose, concave, hollow, stove in, retiring, retreating, cavernous, porous, infundibul, infundibular, infundibuliform, funnel shaped, bell shaped, campaniform, capsular, vaulted, arched.