naive

or naïve

or na·ïve (nī-ēvˈ, nä-) also na·if or na·ïf (nī-ēfˈ, nä-)

1. Lacking worldly experience and understanding, especially:
   a. Simple and guileless; artless: a child with a naive charm.
   b. Unsuspecting or credulous: “Students, often bright but naive, bet—and lose—substantial sums of money on sporting events” (Tim Layden).
2. Showing or characterized by a lack of sophistication and critical judgment: “this extravagance of metaphors, with its naive bombast” (H.L. Mencken).
3. a. Not previously subjected to experiments: testing naive mice.
   b. Not having previously taken or received a particular drug: persons naive to marijuana.

Related Forms:

• na·iveˈly adverb

• na·iveˈness noun