noun, plural si·nus·es.
- any of various cavities, recesses, or passages, as a hollow in a bone, or a reservoir or channel for venous blood.
- one of the hollow cavities in the skull connecting with the nasal cavities.
- an expanded area in a canal or tube.
Origin of sinus
Examples from the Web for sinus
Contemporary Examples of sinus
A fair number explicitly ask for an antibiotic, to cover the possibility that it is “bronchitis” or a “sinus infection.”Without Education, Antibiotic Resistance Will Be Our Greatest Health Crisis
December 19, 2014
Benign secondary headaches include headaches associated with the cold, flu, or sinus infections.How to Destroy Your Headaches
Dr. Anand Veeravagu, MD, Tej Azad
June 23, 2014
First of all, migraines often are misdiagnosed as sinus headaches.Why Everything from Frigid Temperatures to Lightning Can Induce Migraines
January 8, 2014
One of the entries reads: “I spoke with a doctor for a long time about my sinus infections.”To Dream a Dream: Georges Perec’s Night Visions
December 26, 2013
Historical Examples of sinus
He has no bag like the Hebrew slinger, no sinus like the Roman.
He inserted the glowing jewel in the folds of the sinus of her dress.A King of Tyre
James M. Ludlow
When there is a notch or sinus at the anterior extremity, it is said to be emarginated.A Conchological Manual
George Brettingham Sowerby
The symbol sv for sinus versus occurs in the Clavis of 1631.William Oughtred
A process of the face, which enters the notch or sinus of the eye.An Introduction to Entomology: Vol. III (of 4)
noun plural -nuses
- any bodily cavity or hollow space
- a large channel for venous blood, esp between the brain and the skull
- any of the air cavities in the cranial bones
Word Origin for sinus
"hollow curve or cavity in the body," early 15c., from Medieval Latin sinus, from Latin sinus "bend, fold, curve, a bent surface; a bay, bight, gulf; a fold in land;" also "fold of the toga about the breast," hence "bosom," and figuratively "love, affection, intimacy; interior, inmost part;" of unknown origin.