Etymology The verb is first attested in 1530, the adjective in 1626; borrowed from Latin attenuātus, the perfect passive participle of attenuō (see -ate (verb-forming suffix) and -ate (adjective-forming suffix)), from ad- (“to, towards, at”) + tenuo (“to make thin”), itself from tenuis (“thin”) + -ō (verb-forming suffix).
To 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
To 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:
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
To become thin or fine; to grow less.
4
To 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
To rarefy.
"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
Medicine, Sciences To reduce the virulence of a bacterium or virus.
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:
Etymology The verb is first attested in 1530, the adjective in 1626; borrowed from Latin attenuātus, the perfect passive participle of attenuō (see -ate (verb-forming suffix) and -ate (adjective-forming suffix)), from ad- (“to, towards, at”) + tenuo (“to make thin”), itself from tenuis (“thin”) + -ō (verb-forming suffix).
1
Slender, thin.
2
In consistency Rarefied, thin, refined.
3
Biology, Botany, Natural sciencesOf leaves Gradually tapering into a petiole-like extension toward the base.