Attenuation meaning : A gradual diminishing of strength. A reduction in the level of some property with distance, especially the amplitude of a wave or the strength of a signal. A weakening in the virulence of a pathogen or other microorganism. The tapering of a leaf etc to a fine point. A fabrication process in which a material is stretched out into a thin shape. The reduction of the active principles of medicines to minute doses. The proportion of sugar that is converted to ethanol by a yeast.