| 释义 |
precursor|prɪˈkɜːsə(r)|
Also 6–7 præ-; 7 -cursoure, -curser.
[a. L. præcursor forerunner, advanced guard, agent-n. from præcurrĕre to run before; cf. F. précurseur (15th c.).]
1. a. One who or that which runs or goes before; a forerunner; esp. one who precedes and heralds the approach of another; a harbinger; spec. applied to John the Baptist. Also attrib.
1504Lady Margaret tr. De Imitatione iv. xvii. 281 The right excellent precursor Iohn Baptyste. 1612Jas. I in Ellis Orig. Lett. Ser. i. III. 106, I knowe this wilbe the more wellcome that it is my præcursoure. 1792A. Young Trav. France I. 179 Abbé Raynal, one of the undoubted precursors of the present revolution in France. 1852A. Jameson Leg. Madonna (1857) 9 The Baptist is here in his character of Precursor. 1856Miss Mulock J. Halifax xxiii, Shame, the precursor of saving penitence. 1869Dunkin Midn. Sky 173 In ancient times Procyon..was called the Precursor Dog. 1871Tyndall Fragm. Sc. (1879) I. ii. 55 That dark radiation, which is the precursor..of their luminous rays.
†b. Irish Politics. See quots. Obs.
1847Tait's Mag. XIV. 643 Conservatives 39, Repealers 37, Whigs 17, Precursors 12. The precursors are understood to be gentlemen in the transition state towards repeal. 1907Daily Chron. 4 Sept. 4/7 Precursor was one of the many names that O'Connell gave to his popular organisations. The ‘Precursor Society’ meant that it was the precursor of O'Connell's last resource—the Repeal of the Union.
2. One who precedes in some course or office.
1792Burke in Ellis Orig. Lett. Ser. ii. IV. 540 Sufferers in one Common Cause, and..our precursors in misfortune. 1835I. Taylor Spir. Despot. vi. 248 There is now no need that we should err as our precursors have done for want of experience. 1879M. Arnold Mixed Ess., Guide Eng. Lit. 202 Cowper..by his genuine love of nature was a precursor of Wordsworth.
3. Biochem. and Chem. A compound which precedes another in a metabolic pathway or a chemical synthesis, esp. a naturally occurring one.
1889C. A. MacMunn Outl. Clin. Chem. Urine iii. 36 Although we know it [sc. urea] is formed from proteids, we cannot trace it back through its precursors—the intermediate products of metabolism. 1890L. C. Wooldridge tr. G. von Bunge's Text-bk. Physiol. & Path. Chem. vi. 102 This compound is doubtless the precursor of haemoglobin, for there is no considerable quantity of any other compound of iron in the yolk. 1948Jrnl. Biol. Chem. CLXXII. 651 (heading) Homoserine as a precursor of threonine and methionine in Neurospora. 1960[see cryptoxanthin]. 1971Nature 30 July 304/1 An important feature of the process is the maintenance of the high orientation in the acrylic precursor throughout the carbonization processes. 1977Sci. Amer. July 40/2 Ozone and its precursor, atomic oxygen, are destroyed by catalytic reactions that depend on H and OH.
Hence † preˈcursorism, the principles and practice of the Irish ‘precursors’ (see precursor 1 b).
1839John Bull 29 Apr., Otherwise what need would there be for ‘Precursorism’ and ‘Repeal’? 1839Times 17 Sept., Precursorism has turned out to be utterly hopeless. |