lacuna
(ləˈkjuːnə)
Pl. lacunæ, lacunas.
[a. L. lacūna a hole, pit, f. lacus lake n.4 Cf. lacune.]
1. In a manuscript, an inscription, the text of an author: A hiatus, blank, missing portion. Also transf.
| 1663 Sir R. Moray in Lauderd. Papers (Camden) I. 181 You do well to leave no Lacunas in your letters. 1694 Gibson in Lett. Lit. Men (Camden) 228 The lacuna of his behaviour in Holland, Dr. Gregory perhaps may be able to make up. 1851 D. Wilson Preh. Ann. iv. v. (1863) II. 326 The context which fills up the numerous lacunae of the time-worn inscription. 1875 Maine Hist. Inst. ix. 256 The description given..is followed by a lacuna in the manuscript. 1892 Zangwill Bow Myst. 147 There were various lacunæ and hypotheses in the case for the defence. |
2. Chiefly in physical science: A gap, an empty space, spot, or cavity. a. gen.
| 1872 Proctor Ess. Astron. xxiv. 303 The gaps and lacunae are left relatively clear of lucid stars. 1879 Rutley Study Rocks x. 107 Fluid lacunae..are of frequent occurrence in nepheline. 1880 Sat. Rev. 15 May 637 The curious lacuna in the field of vision, known as the blind spot. |
b. Anat. ‘A mucous follicle; also, a space in the connective tissue giving origin to a lymphatic’ (Syd. Soc. Lex. 1888).
| 1706 Phillips (ed. Kersey), Lacunæ are certain small Pores or Passages in the Neck of the Womb. 1722 Quincy Lex. Physico-Med. (ed. 2) 175 Between this Muscle [Sphincter] and the inner membrane of the Vagina, there are several little Glands, whose excretory Ducts are called Lacunæ. 1874 Van Buren Dis. Genit. Org. 77 Inflammation seals the orifice of the follicle and the lacuna is converted into a cyst containing pus. |
c. Anat. One of the small cavities in the bone substance which contain the bone corpuscles or osteoblasts (Syd. Soc. Lex. 1888).
| 1845 Todd & Bowman Phys. Anat. I. 109 They [pores] soon arrange themselves in sets, each of which..discharges itself into a small cavity or lacuna. 1859 [see lacunal a.]. 1867 J. Hogg Microsc. i. ii. 57 The observation of..the Haversian canals and the lacunæ of bones. |
d. Zool. One of the spaces left among the tissues of the lower animals, which serve in place of vessels for the circulation of the body fluids.
| 1867 J. Hogg Microsc. ii. iii. 566 Minute capillary ramifications [in flukes] terminating in small oval shaped sacs or lacunæ. |
e. Bot. An air-space in the cellular tissue of plants, an air-cell. Also, a small pit or depression on the upper surface of the thallus of lichens.
| 1836 Loudon Encycl. Plants 948 [Lichens] Lacunæ are small hollows or pits on the upper surface of the frond. 1856 in Henslow Dict. Bot. Terms. 1874 Cooke Fungi 41 In Tuburcinia, the minute cells are compacted into a hollow sphere, having lacunæ communicating with the interior. |