Forms: 4–7 ardure, 5 ardeur, 7– ardour, -or. [a. OF. and AF. ardour, earlier OF. ardor, -ur, mod. ardeur:—L. ardōrem heat, f. ardē-re to burn. The spelling ardor, assimilated to L., has been in use since 16th c.]
1. Fierce or burning heat; concr. fire, flame.
c. 1645. Howell, Lett., I. xxix. 41. That grand Universal-fire … may by its violent ardor vitrifie and turn to one lump of Crystal, the whole Body of the Earth.
1670. Cotton, Espernon, II. VIII. 409. To qualifie the excessive ardours of the Sun.
1755. B. Martin, Mag. Arts & Sc., 103. A Degree of Ardour equal to that at the Comet.
1814. Cary, Dante, 80. Within these ardours are the spirits, each Swath’d in confining fire.
† 2. poet. An effulgent spirit. (Cf. Heb. i. 7.) Obs.
1667. Milton, P. L., V. 249. The wingéd Saint … from among Thousand Celestial ardors … up springing light.
3. fig. Heat of passion or desire, vehemence, ardent desire; warmth of emotion, zeal, fervor, eagerness, enthusiasm. Const. for. (The earliest sense in Eng.: formerly used of evil passions, but now only of generous or noble impulses.)
c. 1386. Chaucer, Pers. T., ¶ 84. The wicked enchaufing or ardure [v.r. ordure, ordour] of this sinne.
1483. Caxton, Gold. Leg., 240/4. The Ardeur and brennyng of lecherye.
1602. Shaks., Ham., III. iv. 86. When the compulsiue Ardure giues the charge.
1644. Milton, Educ. (1738), 137. Infusing into their young breasts such an ingenious and noble ardour.
1678. Marvell, Growth Popery, Wks. 1875, IV. 313. This dispute was raised to a greater ardure and contention than ever.
1756. Burke, Vind. Nat. Soc., Wks. I. 14. And feel such refreshing airs of liberty, as daily raise our ardour for more.
1769. Robertson, Chas. V., III. IX. 139. Hurried on by a martial ardor.
1819. J. Q. Adams, in C. Davies, Metric Syst., III. 131. Inquiries … pursued with ardor and perseverance.
1847. J. Wilson, Recr. Chr. North (1857), II. 9. The bright ardours of boyhood.
