I was once, I remember, called to a Patient, who had received a violent Contuſion in his Tibia, by which the exterior Cutis was lacerated, ſo that there was a profuſe ſanguinary Diſcharge; and the interior Membranes were ſo divellicated, that the Os or Bone very plainly appeared through the Aperture of the Vulnus or Wound. 1749, Henry Fielding, “Containing the great Address of the Landlady; the great Learning of a Surgeon, and the solid Skill in Casuistry of the worthy Lieutenant”, in The History of Tom Jones, a Foundling, volume III, London: A[ndrew] Millar, […], →OCLC, book VII, page 109:
Etymology tree
Proto-Indo-European *h₁óh₃s
Proto-Italic *ōs
Latin ōsubor.
English os
Unadapted borrowing from Latin ōs (“mouth”).
Meanings
(sometimes) An opening or entrance to a passage, particularly one at either end of the cervix, internal (to the uterus) or external (to the vagina).
The instrument closed, as seen in Fig. 1, is then passed along the finger to the os, in and through the cervix up to the fundus of the uterus, which may be determined both by the distance and the resistance to the broad rounded head of the Capiat. 1891, Texas Medical Association, Transactions, volume 23, page 175:
[…] monocolpate (“unisulcate”) pollen grains still have a continuous aperture membrane devoid of special openings (ora) in the exine for the emergence of the pollen tube. 2009 July 6, Armen Takhtajan, Flowering Plants, Springer Science & Business Media, →ISBN: