It's in mine:
na·ive /nɑˈiv/ Pronunciation Key - Show Spelled Pronunciation[nah-eev] Pronunciation Key - Show IPA Pronunciation
1. having or showing unaffected simplicity of nature or absence of artificiality; unsophisticated; ingenuous.
2. having or showing a lack of experience, judgment, or information; credulous: She's so naive she believes everything she reads. He has a very naive attitude toward politics.
3. having or marked by a simple, unaffectedly direct style reflecting little or no formal training or technique: valuable naive 19th-century American portrait paintings.
4. not having previously been the subject of a scientific experiment, as an animal.
[Origin: 1645–55; < F, fem. of naïf, OF naif natural, instinctive < L nātīvus native]