attenuated

adj. made thin; tapered; reduced; weakened

v. become thin or less; diminish in intensity, decrease, reduce severity

"Attenuated" redirects here. For the bacterial use of the term, see Attenuator (genetics)The verb "attenuate" means "to become weak."Attenuation in virology is reducing the virulence of a virus, whilst keeping it viable (or 'live'), for the purpose of creating a vaccine. It is the counterpart of the vaccines produced by 'killing' the virus (inactivated vaccine)
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Adjective
1. of an electrical signal; reduced in amplitude with little or no distortion
(similar) decreased, reduced
(classification) electronics
2. reduced in strength; "the faded tones of an old recording"
(synonym) attenuate, faded, weakened
(similar) decreased, reduced

Verb
1. weaken the consistency of (a chemical substance)
(synonym) rarefy
(hypernym) weaken
(derivation) attenuation
(classification) chemistry, chemical science
2. become weaker, in strength, value, or magnitude
(hypernym) weaken
(hyponym) refine
(derivation) attenuation, fading
Adjective
1. reduced in strength; "the faded tones of an old recording"
(synonym) attenuated, faded, weakened
(similar) decreased, reduced

(imp. & p. p.)
of Attenuate
  

(a.)
Made thin or slender.
  

(a.)
Made thin or less viscid; rarefied.
  

Weakened or thinned. Attenuated strains of disease-causing bacteria and viruses are often used as vaccines. The weakened strains are used as vaccines because they stimulate a protective immune response while causing no disease or only mild disease in the person receiving the vaccine.