| 释义 |
▪ I. bulb, n.|bʌlb|
Also 7 bulbe.
[ad. Lat. bulb-us a. Gr. βολβός onion, bulbous root.]
†1. An onion. Obs.
1568Turner Herbal ii. 62 The roote wtin is whyte rounde and knoppy after the lyknes of a bulb. 1578Lyte Dodoens v. lxxvii. 644 Lyke an Onyon or Bulbe. 1601Holland Pliny II. 329 Asses milke warme, or sodden together with bulbe roots. a1712King Orpheus & E. (Misc.) 394 Iesuit Bulbs ty'd up with Ropes.
2. Bot.
a. The underground spheroidal portion of the stem of an onion, lily, or other plant of analogous mode of growth; formerly, and still in popular language, regarded as a kind of ‘root’, but by modern botanists defined either as ‘a subterranean bud..sending off roots from below and a stem above’, or as ‘a very short stem, producing roots below, and leaves in the form of scales above’. Sometimes popularly applied to a solid tuber of similar external shape.
1664Evelyn Sylva (1679) Advt., Bulbs, round or onion-shap'd roots. 1712tr. Pomet's Hist. Drugs I. 100 Chuse such Roots or Bulbs, as are sound. 1794Martyn Rousseau's Bot i. 24 The roots are bulbs of some sort or other. 1858Carpenter Veg. Phys. §119 Bulbs..are in reality underground stems in the state of buds. 1884Bower & Scott De Bary's Phaner. & Ferns 142 There lies..on the outer side of the..scales of the bulb, one prismatic crystal.
b. An axillary leaf-bud of bulbous form which detaches itself from the stem, becoming an independent plant, a bulbil.
1845Lindley Sch. Bot. x. (1858) 162 When they [leaf-buds] disarticulate from the stem..they are called bulbs. 1862Huxley Lect. Wrkg. Men 84 A little bulb or portion of the plant drops off, detaches itself and becomes capable of growing as a separate thing.
3. transf. Anat. A roundish dilatation of any cylindrical organ or structure in an animal body, e.g. central bulb, ‘the bulbous extremity of a nerve-fibril in a corpuscle of Krause’; olfactory bulb, the anterior oval termination of the olfactory tract; auditory bulb, the membranous labyrinth and the cochlea together; bulb of the hair, the soft enlargement of the root end of the hair; bulb of spinal marrow, the medulla oblongata.
1715Phil. Trans. XXIX. 327 The Bulb of the Pulmonary Vein..was extraordinarily dilated. 1758J. S. Le Dran's Obs. Surg. (1771) 261 The End of the Bulb of the Urethra. 1813J. Thomson Lect. Inflam. 614 The small bulbs which surround the roots of the hair. 1870Rolleston Anim. Life Introd. 46 The olfactory bulbs are absent.
4. a. A bulb-like dilatation of a glass tube. Also (rarely) a lump of metal of bulbous shape. In full (electric) light bulb; the glass bulb-shaped container of the incandescent filament used for producing electric light.
1800Vince Hydrostat. x. (1806) 95 A glass tube with a bulb at the bottom. 1831Brewster Optics x. 89 The bulb of the thermometer. 1833J. Holland Manuf. Metals II. 302 The metal bulb, which is moved along the graduated line of the lever, to ascertain the weight. 1856Enquire within on Ev. (1862) 278 Glass water bulbs..are sold by men in the London streets at one penny each. 1856National Rev. July 88 The ray of the electric bulb, so sharply defined that all beyond its pencil falls into depth of darkness. 1882Electric Light 1 Sept. 70/1 Volatilized carbon being deposited on the inside of the bulb. 1884Daily News 3 Sept. 3/1 The bower is illuminated by two Edison incandescent electric light bulbs. 1890J. W. Urquhart Electric Light Fitting 170 It becomes a question whether it is economical to run such blackened bulbs longer after a certain percentage of light has been so cut off. 1964V. S. Naipaul Area of Darkness v. 110 A large bulb..was attached to a stunted flexible arm..: this was the lamp.
b. bulb of percussion, the convex protuberance on the fractured surface of a flint.
1872J. Evans Anc. Stone Impl. xii. 247 Where a splinter of flint is struck off by a blow, there will be a bulb or projection, of a more or less conical form, at the end where the blow was administered... This projection is usually known as the ‘bulb of percussion’. 1923Discovery Dec. 316/2 Even the bulb of percussion which arises when a flint is broken by a violent blow, owing to the elasticity of its substance, can be produced by [natural] forces.
c. A pneumatic rubber bulb-shaped device on syringes, camera-mechanisms, etc.
1885Army & Navy Co-op. Soc. Price List 874 The bulb can be disconnected, and fitted to any of the pipes as an Injection Bottle. 1911Encycl. Brit. XXI. 514/2 J. Cadett's system of pneumatic pressure, applied by means of a compressible rubber bulb and tube, which may drive a piston acting on the lever holding the shutter. 1966McGraw-Hill Encycl. Sci. & Technol. II. 431/2 Arrangements are made for keeping the shutter open for long times if needed (bulb and time or B and T). 1968Listener 19 Dec. 811/3 He took from his pocket..a small glass instrument with a rubber bulb at the end. With this bulb he sucked some of the whisky into the tube.
5. Comb., as bulb-like adj.; also bulb-fin, bulb-keel, a keel of a yacht having a cigar-shaped attachment which in section presents a bulb-like appearance; also ellipt. a yacht having such an attachment; bulb-iron, angle-iron (Mech.), a bulbed iron or angle-iron used to strengthen joints or angles in the framework of ships; bulb-scales (see quot.); bulb-tube, a tube terminating in a bulb.
1894E. R. Sullivan et al. Yachting I. 91 She was very deficient in stability when the lead slab forming the keel was recast in the form of a bulb on the bottom of the plate, the completed design simply forming one of our modern *bulb fin keels. 1895Outing (U.S.) Sept. 481/1 The great bulb-fins Jubilee and Pilgrim.
1869E. J. Reed Ship Build. i. 10 To introduce separate straps for the *bulb-irons. Ibid. viii. 138 A bulb angle-iron has been used for the deck beam.
1893*bulb keel [see fin n.1 6].
1927R. A. Freeman Certain Dr. Thorndyke i. ix. 136 Spoon-bows and bulb keels were things as yet undreamed of.
1836–9Todd Cycl. Anat. & Phys. II. 962/1 A soft *bulb-like extremity.
1882Vines Sachs' Bot. 714 The *bulb-scales of the Tulip. 1839–47Todd Cycl. Anat. & Phys. III. 818/2 The contents of the *bulb-tube are emptied into a small evaporating dish.
Add:[2.] [a.] For last sentence of def. read: Sometimes popularly applied to a solid tuber of similar external shape and by metonymy, esp. in Gardening, to a plant which grows from a bulb.
1727Bradley's Fam. Dict. s.v. Cyclamen, The German Cyclamens are rather Turnep-rooted Plants than Bulbs. 1821Bot. Reg. VII. App. 7 Other points of agreement with Crinum separate them [sc. the plants] still more widely from the occidental bulbs which I have heretofore called Amaryllis. 1901W. Robinson Eng. Flower Garden (ed. 8) 162 A great number of our spring flowers and hardy bulbs mature their foliage and go to rest early in the year. 1988Gardening from ‘Which?’ Aug. 245/1 Some autumn-flowering bulbs are suitable for partial shade.
▪ II. bulb, v.|bʌlb|
[f. prec.]
intr. a. To swell into a bulb-like or rounded form. b. To form a bulb-shaped root.
1681Cotton Wond. Peak (ed. 4) 11 Bulbing out in figure of a sphere. 1846Hannam in Jrnl. R. Agric. Soc. VII. ii. 589 The turnips did not bulb well. 1886Dagonet the Jester ii. 73 How sweetly bulbeth out the figure of Psyche as she looks into the lamp. |