With ingenuous frankness he spoke of what a wicked, ill-disciplined boy he had been, and impulsively drew up his cuff to exhibit upon his wrist the scar from a saber cut which he had received in a duel outside of Paris when he was nineteen.
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She plays a wide-eyed, ingenuous schoolgirl forced to grow up too quickly.
The face of the old man was stern, hard-featured, and forbidding; that of the young one, open, handsome, and ingenuous.
Dickens, Charles -- The Life and Adventures of Nicholas Nickleby