Pl. fenestræ. [L. fenestra window, f. root of Gr. φαίνειν to show.] A small hole or transparent spot resembling a hole.
1. Anat. A small hole or opening in a bone, etc.; esp. applied to the two openings on the inner wall of the tympanum of the ear, fenestra ovalis, rotunda (see quot. 1884).
1844. Hoblyn, Dict. Med. Terms, 121/1. Fenestra ovalis and rotunda are respectively synonymous with foramen ovale and rotundum, or the oval and round apertures of the internal ear.
1854. Owen, Skel. & Teeth (1855), 33. The alisphenoids, form the anterior half of the fenestra ovalis.
1870. Rolleston, Anim. Life, 7. An interorbital fenestra.
1877. Huxley, Anat. Inv. Anim., vii. 400. An oval fenestra, covered only by a thin and transparent portion of the integument.
1884. Barr, Dis. Ear, III. i. 260. The fenestra ovalis or opening into the vestibule and the fenestra rotunda or opening into the cochlea. The fenestra ovalis is in the upper and back part of the inner wall … at the bottom of a recess … The fenestra rotunda … is also situated at the bottom of a recess in the bone.
2. Zool. (See quot.)
1881. Vines, in Nature, No. 620. 463. Fenestræ … openings [in the zoarium] … connected by the general substance of the zoarium.
3. Bot. See quot. Also ‘an opening through a membrane’ (Treas. Bot., 1866).
1828. Stark, Elem. Nat. Hist., II. 459. The part at which the seed has separated from the ovary is indicated by a small mark or scar, called fenestra.
