1. (

• unquestionable

) incapable of being questioned; "unquestionable authority" ;

2. (

• authentic ,
• bona_fide ,
• unquestionable ,
• veritable

) not counterfeit or copied; "an authentic signature"; "a bona fide manuscript"; "an unquestionable antique"; "photographs taken in a veritable bull ring" ;

3. (

• unquestionable

) not open to question; "an unquestionable (or unequivocal) loss of prestige" ;