unˈdoubtfully,adv. [un-1 11; cf.prec.] † Without doubt; indubitably. 1628Verstegan Dec. Intell. ii. 51 Such as so persuade themselues are therin vndoubtfully deceiued.1629Lynde Via Tuta 251 Little can be said of any certainty, or as vndoubtfully true.