ingenuous

Adjective

• lacking in sophistication or worldliness
  • a child's innocent stare
    
  • his ingenuous explanation that he would not have burned the church if he had not thought the bishop was in it
    

• characterized by an inability to mask your feelings; not devious
  • an ingenuous admission of responsibility
    

Related words

• Synonyms: 
  innocent , artless
• Antonyms: 
  disingenuous , artful