Words: naïve [MW]

Function: adjective
Etymology: French naïve, feminine of naïf, from Old French, inborn, natural, from Latin nativus native
1 : marked by unaffected simplicity : ARTLESS, INGENUOUS
2 a : deficient in worldly wisdom or informed judgment; especially : CREDULOUS b : not previously subjected to experimentation or a particular experimental situation "made the test with naive rats"; also : not having previously used a particular drug (as marijuana)
3 : SELF-TAUGHT, PRIMITIVE
synonym see NATURAL: NAIVE suggests lack of worldly wisdom often connoting credulousness and unchecked innocence "politically naive"