attenuate

present singular third person attenuates · participle present attenuating · participle past attenuated · past attenuated

1. transitiveTo reduce in size, force, value, amount, or degree.

   A manor-house clock from the far depths of shadow struck the hour, one, in a small, attenuated tone.

   1874, Thomas Hardy, chapter 40, in Far From the Madding Crowd

2. transitiveTo make thinner, as by physically reshaping, starving, or decaying.

   Clumps of attenuated turkeys were suspended here and there.

   1899, Stephen Crane, chapter 4, in His New Mittens

   1 more example

   Lovell, wan and hollow-eyed, his arm in a sling, his once burly frame gaunt and attenuated with disease, nodded.

   1906, E. Phillips Oppenheim, chapter 1, in The Malefactor

3. intransitiveTo become thin or fine; to grow less.
4. transitiveTo weaken.

   We may reject and reject till we attenuate history into sapless meagreness.

   1851, Sir Francis Palgrave, chapter IV, in The History of Normandy and of England

5. transitiveTo rarefy.

   1 more example

   "It speedily became apparent that the entire strangeness of our circumstances and surroundings—great loss of weight, attenuated but highly oxygenated air, consequent exaggeration of the results of muscular effort, rapid development of weird plants from obscure spores, lurid sky—was exciting my companion unduly."

   1900 December – 1901 August, H[erbert] G[eorge] Wells, chapter 23, in The First Men in the Moon, London: George Newnes, […], published 1901, →OCLC

6. transitivemedicineTo reduce the virulence of a bacterium or virus.
7. transitivebusinessTo reduce the amplitude of an electrical, radio, or optical signal.
8. beveragesOf a beer, to become less dense as a result of the conversion of sugar to alcohol.

   A beer which does not attenuate to the expected level in fermentation will have more residual sugar and thus be sweeter and heavier-bodied.

   2009 July–August, John Palmer, “Attenuation: Advanced Brewing”, in Brew Your Own, archived from the original on 06 Oct 2013

comparative more attenuate · superlative most attenuate

1. Slender, thin.
2. Rarefied, thin, refined.
3. biologyGradually tapering into a petiole-like extension toward the base.