▪ I. ‖ cirrus
(ˈsɪrəs)
Erroneously cirrhus.
[L. cirrus curl, fringe, etc.]
‖ 1. lit. A curl-like tuft, fringe, or filament.
| 1708 Phillips, Cirrus, a Tuft or Lock of Hair curled. |
2. Bot. A tendril: see quots. 1845, 1870.
| 1708 Phillips, Cirri are also taken for these fine Strings, or Hairs, by which some Plants fasten themselves; in order to their Support in creeping along; as Ivy, etc. 1845 Lindley Sch. Bot. i. (1858) 10 The midrib [of the leaf] is lengthened, and acquires the power of twining round small bodies..it then has the name of cirrhus or tendril. 1870 Bentley Bot. 103 Tendril or Cirrhus is applied to a thread-like leafless branch, which is twisted in a spiral direction. |
3. Zool. A slender or filamentary process or appendage, as the fleshy barbel or beard of some fishes, the feet of Cirripedes, the lateral processes on the arms of Brachiopoda, etc.
| 1753 Chambers Cycl. Supp., Cirrus, certain oblong and soft appendiculæ hanging from the under jaw of fishes. 1828 Stark Elem. Nat. Hist. II. 126 Tubinicella, body inclosed in a shell, with the cirri small, setaceous, and unequal. 1834 Sir C. Bell Hand 147 Fishes have cirri which hang from their mouth. 1834 M{supc}Murtrie Cuvier's Anim. Kingd. 274 [In barnacles] the mouth is at the bottom and the cirri near the orifice. 1877 Huxley Anat. Inv. An. v. 231 In some somites this appendage is a cirrus. |
4. Meteorol. A form of cloud, generally at a high elevation, presenting the appearance of diverging filaments or wisps, often resembling a curl or lock of hair or wool. Particular varieties are known as cat's or mare's tails. See cirro- 2.
| 1803 L. Howard Modif. Clouds (1865) 2–3 It may be allowable to introduce a Methodical nomenclature, applicable..to the Modifications of Cloud..Cirrus, parallel, flexuous, or diverging fibres, extensible by increase in any or in all directions. 1815 T. Forster Res. Atmosph. Phenom. iv. §3. 143 When the cirrus is seen in detached tufts, called Mare's Tails, it may be regarded as a sign of wind. 1866 Cornh. Mag. Nov. 565 The moon..disc-hid In a gossamer veil of white cirrhus. 1874 Hartwig Aërial W. 158 The cirrus or curl-cloud has its seat in the higher regions. |
5. attrib. and in Comb., as cirrus-cloud, cirrus-flecked adj. (sense 4); cirrus-bag, ‘the sheath containing the cirrus of trematode and other worms’.
| 1864 R. Burton Dahome 17 The cirrus-flecked nocturnal sky. 1878 Huxley Physiogr. 42 The cirrus clouds are..sometimes as much as ten miles above the surface of the earth. |
▪ II. cirrus
? obs. f. (or misprint) of ceruse n.
| 1626 Bacon Sylva §291 Metalls..in their Putrefactions, or Rusts; as Vermilion, Verdegrease, Bise, Cirrus. |