Source : Webster's Revised Unabridged Dictionary (1913)

Instructive \In*struct"ive\, a. [Cf. F. instructif.]
   Conveying knowledge; serving to instruct or inform; as,
   experience furnishes very instructive lessons. --Addison.

         In various talk the instructive hours they past.
                                                  --Pope.
   -- {In*struct"ive*ly}, adv. -- {In*struct"ive*ness}, n.

         The pregnant instructiveness of the Scripture. --Boyle.

Source : WordNet®

instructive
     adj 1: serving to instruct of enlighten or inform [syn: {informative}]
            [ant: {uninstructive}]
     2: tending to increase knowledge or dissipate ignorance; "an
        enlightening glimpse of government in action" [syn: {enlightening},
         {informative}] [ant: {unenlightening}]