|ən+ adjective
: not impeachable : not to be called in question : exempt from liability to accusation : irreproachable , blameless
an unimpeachable reputation
information from an unimpeachable source
an easy and unimpeachable literary style
• un·im·peach·able·ness -əbəlnə̇s noun -es
• un·im·peach·ably -əblē adverb