sinus •pandanus •badness, madness, sadness •Magnus • aptness •fatness, patness •redness • wetness •anus, Coriolanus, heinous, Janus, Punta Arenas, Silvanus •genus, intravenous, Maecenas, Malvinas, Salinas, venous, Venus •Cygnus • proteinous • ruinous •libidinous •multitudinous, platitudinous, pulchritudinous, vicissitudinous •cartilaginous, farraginous, oleaginous •fuliginous, indigenous, oxygenous, polygynous, rubiginous, vertiginous •androgynous, autogenous, endogenous, erogenous, exogenous, homogenous, hydrogenous, misogynous •ferruginous • ominous •bituminous, leguminous, luminous, numinous, voluminous •conterminous, coterminous, terminus, verminous •larcenous • gelatinous • cretinous •mountainous •glutinous, mutinous •resinous •Aquinas, Delphinus, echinus, Linus, Longinus, minus, Plotinus, sinus, vinous •oddness • wanness • hotness •Faunus, rawness •Kaunas •bonus, Cronus, Jonas, lowness, onus, Tithonus •oldness •newness, twoness •fulness •alumnus, rumness •oneness • Oceanus • Eridanus •diaphanous • polyphonous •cacophonous, homophonous •porcellanous • villainous •membranous • tyrannous •synchronous • Uranus • tetanus •monotonous • gluttonous •cavernous, ravenous •treasonous • poisonous • Avernus

si·nus / ˈsīnəs/ • n. 1. (often sinuses) Anat. & Zool. a cavity within a bone or other tissue, esp. one in the bones of the face or skull connecting with the nasal cavities. ∎  an irregular venous or lymphatic cavity, reservoir, or dilated vessel. ∎  Med. an infected tract leading from a deep-seated infection and discharging pus to the surface. ∎  Bot. a rounded notch between two lobes on the margin of a leaf or petal. 2. [as adj.] Physiol. relating to or denoting the sinoatrial node of the heart or its function as a pacemaker: sinus rhythm sinus tachycardia.

sinus (sy-nŭs) n.
1. an air cavity within a bone, especially any of the cavities within the bones of the face or skull (see paranasal sinuses).

2. any wide channel containing blood, usually venous blood. s. arrhythmia see arrhythmia. s. rhythm a normal heart rhythm, usually as recorded on an electrocardiogram. s. venosus a chamber in the embryonic heart that becomes part of the right atrium after birth.

3. a pocket or bulge in a tubular organ, especially a blood vessel.

4. (sinus tract) a blind-ending infected tract leading from a focus of infection to the surface of the skin or a hollow organ. See pilonidal sinus.

sinus A Latin word meaning ‘curve’ or ‘bay’.
1. The word ‘sinus’ was used by Giovanni B. Riccioli in 1651 to designate bay-like features on the lunar maria (see MARE). The best known example is Sinus Iridum, the ‘Bay of Rainbows’, on the north-western margin of the ‘Sea of Rains’ (Mare Imbrium).

2. In certain bivalves (Bivalvia), a recess or embayment in the pallial line; most bivalves with a pallial sinus are burrowers.

sinus
1. A space, found e.g. in certain bones of the face of a mammal where they are filled with air and connect with the nasal cavity.

2. In certain Bivalvia, a recess or embayment in the pallial line; forms with a sinus are generally burrowers.

sinus Hollow space or cavity, usually in bone. Most often the term refers to the paranasal sinuses, any of the four sets of air-filled cavities in the skull near the nose: the maxillary, frontal, ethmoid, and sphenoid. These may become infected and inflamed (sinusitis), causing pain.

sinus A saclike cavity or organ in an animal, such as the sinus venosus.

sinus A space, found for example between the lobes of a plant leaf.

sinus (path.) abscess, etc. XVI; (bot., anat.) cavity, depression XVII. — L. sinus semicircular fold, bosom, bay.