ingenuous
Concise Oxford English Dictionary © 2008 Oxford University Press:
ingenuous /ɪnˈdʒɛnjʊəs/
▶adjective innocent and unsuspecting.
– derivatives
ingenuously adverb,
ingenuousness noun.
ingenuously adverb,
ingenuousness noun.
– origin C16 (orig. in sense ‘noble, generous’): from L. ingenuus lit. ‘native, inborn’.
'ingenuous' also found in these Oxford entries:

