unimpeachably adv 1: without question; "Fred Winter is unquestionably the jockey to follow"; "they hired unimpeachably first-rate faculty members" [syn: {unquestionably}, {unimpeachably}]
Unimpeachable \Un`im*peach"a*ble\, a. Not impeachable; not to be called in question; exempt from liability to accusation; free from stain, guilt, or fault; irreproachable; blameless; as, an unimpeachable reputation; unimpeachable testimony. --Burke. -- {Un`im*peach"a*ble*ness}, n. -- {Un`im*peach"a*bly}, adv. [1913 Webster]