attenuate

at·ten·u·ate

vt \ə-ˈten-yə-ˌwāt\

at·ten·u·at·edat·ten·u·at·ing

Definition of ATTENUATE

: to reduce the severity of (a disease) or virulence or vitality of (a pathogenic agent) <a procedure to attenuate severe diabetes> <attenuated bacilli>