3.Definition: marked by or showing unaffected simplicity and lack of guile or worldly experience
"A teenager's naive ignorance of life", "The naive assumption that things can only get better", "This naive simple creature with wide friendly eyes so eager to believe appearances"
4.Definition: not initiated; deficient in relevant experience
"He took part in the experiment as a naive subject"
5.Definition: of or created by one without formal training; simple or naive in style