1. To reduce the size, strength, or density of something, or to become thinner, weaker, or less densel: "The drought attenuated the river to a narrow channel."
2. To weaken or to reduce in force, the intensity, effect, quantity, or value of something: "Medicine attenuated the fever's effect."

"Deloris was able to attenuate her desire to eat too much."
3. To reduce the virulence of a bacterium or virus: "The chemist was able to attenuate the virus by exposing it to heat or producing a culture of it in a special medium." 4. Etymology: "to make thin, to make less" from Latin attenuatus, past participle of attenuare, "to make thin"; from ad-, "to" + tenuare, "to make thin"; from tenuis, "thin".

1. Rarefied or lessened by the density of.
2. In biology, a reference to bacteria or viruses that are less virulent.
3. In medicine, descriptive of the dilution of a solution or the reduction in virulence or toxicity of a microorganism or a drug by weakening it: "Attenuated bacteria or viruses are used in some vaccines." 4. In electronics, a reference to the reduction of the amplitude of an electrical signal with little or no distortion.