in·struc·tive \-ktiv, -tēv also -təv\adjective Etymology: probably from Middle French instructif, from Latin instructus (past participle) + Middle French -if -ive : conveying knowledge : serving to instruct or inform < experience furnishes very instructive lessons > < such experiences are instructive > • in·struc·tive·ly\-tə̇vlē, -li\adverb • in·struc·tive·ness\-tivnə̇s, -tēv- also -təv-\noun-es