Source : Webster's Revised Unabridged Dictionary (1913)

Manful \Man"ful\, a.
   Showing manliness, or manly spirit; hence, brave, courageous,
   resolute, noble. `` Manful hardiness.'' --Chaucer. --
   {Man"ful*ly}, adv. -- {Man"ful*ness}, n.

Source : WordNet®

manfully
     adv : in a manful manner; with qualities thought to befit a man;
           "having said her say Peggy manfully shouldered her
           burden and prepared to break up yet another home" [syn:
            {manly}] [ant: {unmanfully}]