from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A depression or cavity formed by a bending or curving.
  • n. Anatomy A dilated channel or receptacle containing chiefly venous blood.
  • n. Anatomy Any of various air-filled cavities in the bones of the skull, especially one communicating with the nostrils.
  • n. Pathology A fistula leading from a pus-filled cavity.
  • n. Botany A recess or indentation between lobes of a leaf or corolla.

from Wiktionary, Creative Commons Attribution/Share-Alike License

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

from the GNU version of the Collaborative International Dictionary of English

  • n. An opening; a hollow; a bending.
  • n. A bay of the sea; a recess in the shore.
  • n. A cavity; a depression.
  • n. A cavity in a bone or other part, either closed or with a narrow opening.
  • n. A dilated vessel or canal.
  • n. A narrow, elongated cavity, in which pus is collected; an elongated abscess with only a small orifice.
  • n. A depression between adjoining lobes.

from The Century Dictionary and Cyclopedia

  • n. A bend or fold; a curving part of anything; a sinuosity; specifically, a bay of the sea; a gulf.
  • n. In anatomy and zoology, a cavity or hollow of bone or other tissue, in the widest sense; a bay, recess, pocket, dilatation, or excavation, generally deeper and less open than a fossa: used with either English or Latin context.
  • n. In pathology, a narrow passage leading to an abscess or other diseased locality; a fistula.
  • n. In botany, the recess or rounded curve between two projecting lobes: as, the sinuses of a repand or sinuate leaf. See cuts under kidney-shaped, pinnatifid, repand, and sinuate.
  • n. The bony air-sinuses of the head. See def. 2 .
  • n. The rhombocœlia. Also called sinus rhomboidalis.
  • n. one of the sinuses of the dura mater (see above), or
  • n. a sinus venosus (see above).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an abnormal passage leading from a suppurating cavity to the body surface
  • n. any of various air-filled cavities especially in the bones of the skull
  • n. a wide channel containing blood; does not have the coating of an ordinary blood vessel


from The American Heritage® Dictionary of the English Language, 4th Edition

Middle English, hollow in the body, from Medieval Latin, from Latin, curve, hollow.

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin sinus.


  • WATERS: The first question I had, and I am sure the Fords are asking the same question too, the president was at Hahnemann Hospital last night complaining of what he described as a sinus infection and wax buildup in the ear.

    CNN Transcript - Breaking News: Fmr. Pres. Ford in Intensive Care After Two Small Strokes - August 2, 2000

  • The coalescence of the neural folds occurs first in the region of the hind-brain, and from there extends forward and backward; toward the end of the third week the front opening (anterior neuropore) of the tube finally closes at the anterior end of the future brain, and forms a recess which is in contact, for a time, with the overlying ectoderm; the hinder part of the neural groove presents for a time a rhomboidal shape, and to this expanded portion the term sinus rhomboidalis has been applied (Fig. 18).

    I. Embryology. 6. The Neural Groove and Tube

  • KNOX: That, he says, will be the next big advance in sinus treatment.

    Surgery For Sinus Misery: Better, But Still No Cure

  • Concrete filled steel profiles follow in sinus waves from the ground level to the top of the tower, creating a distinctive identity and complementing the tower design.

    Dorobanti Tower by Zaha Hadid Architects

  • If the sinus is removed, keeping pressure off of the incision is imperative to good wound healing.

    Pediatric Surgery: Pilonidal Sinus and Cysts

  • One odd thing resulted from the surgery ... now his heart is back in sinus (sp?) rhythm.

    Rough Morning

  • The sinus node generates the electric impulse that starts your heartbeat, so this is known as a sinus rhythm.

    Healing the Female Heart

  • The area innervated by the depressor nerves and the carotid sinus is therefore part of a common system, sometimes called the bridles of the blood pressure.

    Physiology or Medicine 1938 - Presentation Speech

  • He killed it stone dead by thrusting a stiff straw back into the brain through the "little hole in its face," as he called the sinus which leads into the head cavity.

    The Young Alaskans on the Missouri

  • An inflammation of the sinus cavities - rhinosinusitis which is commonly referred to as a sinus infection is a common but expensive condition in the United States.



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