arrested artless babbling backward blithering bluff blunt born yesterday burbling candid childlike confiding crackbrained cracked crazy cretinistic cretinous dim-witted direct dithering driveling drooling dull feebleminded frank guileless half-baked half-witted idiotic imbecile imbecilic ingenu ingenuous innocent maundering mentally defective mentally deficient mentally handicapped mentally retarded mongoloid moronic naive not all there open openhearted outspoken plain retarded simple simplehearted simpletonian sincere single-hearted single-minded slobbering slow slow-witted subnormal trustful trusting unguarded unreserved unsophisticated unsuspicious unwary