Source : Webster's Revised Unabridged Dictionary (1913)

Affirmatory \Af*firm"a*to*ry\, a.
   Giving affirmation; assertive; affirmative. --Massey.

Source : WordNet®

affirmatory
     adj : affirming or giving assent; "an affirmative decision";
           "affirmative votes"; "an affirmative nod"; "an
           affirmatory gesture" [syn: {affirmative}] [ant: {negative}]