1. (

• unimpeachable

) beyond doubt or reproach; "an unimpeachable source" ;

2. (

• blameless ,
• inculpable ,
• irreproachable ,
• unimpeachable

) free of guilt; not subject to blame; "has lived a blameless life"; "of irreproachable character"; "an unimpeachable reputation" ;

3. (

• unexceptionable ,
• unimpeachable

) completely acceptable; not open to exception or reproach; "two unexceptionable witnesses"; "a judge's ethics should be unexceptionable" ;