Sinus
Sinus , noun
[Latin, a bent surface, a curve, the folds or bosom of a garment, etc., a bay. Compare Sine, n.]
1.
An opening; a hollow; a bending.
2.
A bay of the sea; a recess in the shore.
3.
(Anatomy & Zoology) A cavity; a depression.
(a)
(Anatomy & Zoology) A cavity in a bone or other part, either closed or with a narrow opening.
(b)
(Anatomy & Zoology) A dilated vessel or canal.
4.
(Medicine) A narrow, elongated cavity, in which pus is collected; an elongated abscess with only a small orifice.
5.
(Botany) A depression between adjoining lobes.
A sinus may be rounded, as in the leaf of the white oak, or acute, as in that of the red maple.
Collocations (2)
Sinus venosus (Anatomy) , (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.