| 释义 |
deciduous, a.|dɪˈsɪdjuːəs|
[f. L. dēcidu-us falling down, falling off (f. dēcid-ĕre: see decident) + -ous. Cf. mod.F. décidu.]
†1. Falling down or off. Obs.
1656H. More Enthus. Tri. (1712) 32 The Lightnings without Thunder are as it were the deciduous flowers of the æstival Stars.
†b. Sinking, declining, Obs. rare.
1791E. Darwin Bot. Gard. i. 16 Yon round deciduous day, Tressed with soft beams.
2. Bot. and Zool. Of parts of plants or animals (as leaves, petals, teeth, horns, etc.): Falling off or shed at a particular time, season, or stage of growth. Opposed to persistent or permanent.
1688R. Holme Armoury ii. 115/1 Deciduous leaf. 1690Boyle Chr. Virtuoso ii. ii. §i, Which some anatomists therefore call deciduous parts, such as the placenta uterina, and the different membranes that involve the fœtus. 1704J. Harris Lex. Techn., Deciduous, is that which is apt or ready to fall..Thus the Botanists say, in some Plants the Perianthium or Calyx is deciduous with the Flower, i.e. falls from off the Plant with it. 1766Pennant Zool. I. p. xxii, Upright branched horns, annually deciduous. 1784Cowper Task iii. 468 Ere the beech and elm have cast their leaf Deciduous. 1872Huxley Phys. xii. 290 The first set of teeth, called deciduous or milk teeth. 1875Darwin Insectiv. Pl. xv. 353 The deciduous..scales of the leaf buds.
b. Bot. Of a tree or shrub: That sheds its leaves every year; opposed to evergreen.
1778R. Lowth Transl. Isaiah Notes (ed. 12) 144 The oak [and] the terebinth..being deciduous; where the Prophet's design seems to me to require an ever-green. 1816Kirby & Sp. Entomol. (1843) I. 176 The insects injurious to deciduous trees mostly leave the fir and pine tribes untouched. 1875Lyell Princ. Geol. I. ii. xix. 459 The deciduous cypress.
c. Zool. Of insects: That shed their wings after copulation, as the females of ants and termites.
d. Phys. = decidual.
1829Bell Anat. Hum. Body (ed. 7) III. 445 That the ovum..upon its descent gets entangled behind the deciduous membrane. 1868Owen Anat. Vert. III. xxxviii. 725 note, The normal canal of the uterus is obliterated by the accumulated deciduous substance.
3. fig. Fleeting, transitory; perishing or disappearing after having served its purpose.
1811W. R. Spencer Poems Ded., E'en Fancy's rose deciduous dies. 1841–4Emerson Ess., Love Wks. (Bohn) I. 79 They discover that all which at first drew them together..was deciduous. 1870Lowell Among my Bks. Ser. i. (1873) 177 There is much that is deciduous in books.
Hence deˈciduously, deˈciduousness.
1868Owen Anat. Vert. III. xxxviii. 725 The deciduously developed lining substance of the womb. 1727Bailey vol. II, Deciduousness, aptness to fall. 1871Earle Philol. viii. 395 This early deciduousness of our reflex pronoun. |