[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, Anal. Mel., I. ii. III. x. (1651), 111. They crucifie the soul of man, attenuate our bodies.
1668. Culpepper & Cole, trans. 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. Mrs. 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. 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. trans. 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.
1824. Coleridge, Aids Refl. (1829), App. 367 (in Webster). The attention attenuates as its sphere contracts.
