▪ I. attenuate, v.
(əˈtɛnjuːeɪt)
[f. L. attenuāt- ppl. stem of attenuāre, f. at- = ad- to + tenuāre to make thin, f. tenuis thin. Cf. F. atténuer, 12th c.]
1. To make thin or slender in girth or diameter (e.g. by natural or artificial shaping, drawing out, wearing down, starving, physical decay).
| 1530 Palsgr. 440/1, I attenuate, I make thynne, Jattenue. 1621 Burton Anat. Mel. i. ii. iii. x. (1651) 111 They crucifie the soul of man, attenuate our bodies. 1668 Culpepper & Cole tr. Barthol. Anat. i. xvii. 47 The Ureters in their progress are not attenuated within, as other Vessels are. 1794 Sullivan View Nat. I. 47 This shell also being attenuated..the surface of the earth will tumble in. 1848 A. Jameson Sacr. & Leg. Art (1850) 203 The wasted unclad form is seen attenuated by vigils. 1876 Bancroft Hist. U.S. III. iii. 344 To attenuate them by gently drawing them out. |
2. a. To make thin in consistency, to separate the particles of a substance, to diminish density, rarefy.
| 1594 Plat Jewell-ho. i. 40 Earth beeing attenuated becommeth water. 1691 E. Taylor Behmen's Theos. Phil. 187 The Suns lustre attenuateth the gross air. 1756 C. Lucas Ess. Waters I. 48 Burning spirits..are oils attenuated and subtilised by the action of fermentation. 1762 tr. Duhamel's Husb. i. iii. 5 Salt, for example, may attenuate earth. 1874 [see attenuated 2.] |
b. spec. in Med. To render thinner (the humours or concretions of the body).
| 1533 Elyot Cast. Helth ii. xiv. (R.) Dry figges..havinge power to attenuate or make humours currant. 1605 Timme Quersit. i. xiii. 64 O[y]le of pepper doth attenuat..tartarus matters in the body. 1797 Downing Disord. Horn. Cattle 13 These medicines..powerfully attenuate the cloggy disposition of the blood. |
3. fig. To weaken or reduce in force, effect, amount; in value, estimation; (obs.) to extenuate.
| 1530 Palsgr. 440/1 He hath attenuat my power. 1579 Lyly Euphues (Arb.) 49 The delightfulnesse of the one will attenuate the tediousnesse of the other. c 1645 Howell Lett. (1650) I. 335 The Mahometans..attenuated their numbers in Asia. 1660 A. Sidney in Four C. Eng. Lett. 119 To aggravate that, which he doth intend to attenuate. 1850 Q. Rev. June 15 Some Notes..intended to attenuate the authority of the Christian philosopher. 1869 Lecky Europ. Mor. I. i. 117 To attenuate..his own appetites and emotions. |
4. intr. To become slender, thinner, or weaker.
| a 1834 Coleridge (in Webster), The attention attenuates as its sphere contracts. |
5. Electr. To introduce attenuation; in pass., to be subjected to attenuation. Cf. attenuation 4.
| 1886 Lord Rayleigh in Phil. Mag. 5th Ser. XXII. 490 If we had the means of observing the passage of signals at various points of a long cable, we should find them not merely retarded..as we recede from the sending end, but also attenuated. 1892 Heaviside Electr. Papers II. 133 The act of reflection attenuates. Ibid. 346 During transmission along the circuit, the vibrations are attenuated. 1959 Chambers's Encycl. VII. 696/2 The lower part of the Heaviside layer is of particular importance..because it is in this region that radio waves used for long-distance communication are attenuated. |
▪ II. attenuate, ppl. a.
(əˈtɛnjuːət)
[ad. L. attenuātus, pa. pple. of attenuāre: see prec.]
Made thin.
1. Slender, thin; tapered, reduced to thinness.
| 1848 Dana Zooph. 161 Tentacles numerous, attenuate, diaphanous. 1864 Mrs. H. Wood Shadow of Ashlydyat (1878) 433 She saw the white and wan face, the attenuate hands. 1880 Gray Bot. Text-bk. 398 Attenuate, slenderly tapering or narrow. |
2. Thin in consistency, rarefied; refined.
| 1626 Bacon Sylva §938 Such a rare and attenuate substance, as is the spirit of living creatures. 1647 H. More Song of Soul iii. Pref./1 The life of the body..hinders us of the sight of more attenuate phantasmes. 1879 G. Meredith Egoist I. xiv. 255 The idea is too exquisitely attenuate. |