Attenuation

·noun The act or process of making slender, or the state of being slender; emaciation.

II. Attenuation ·noun The process of weakening in intensity; diminution of virulence; as, the attenuation of virus.

III. Attenuation ·noun The act of attenuating; the act of making thin or less dense, or of rarefying, as fluids or gases.