Playful, a. — Webster enters it under “playful”
Sportive; gamboling; frolicsome; indulging a sportive fancy; humorous; merry; as, a playful child; a playful writer. -- Play"ful*ly, adv. -- Play"ful*ness, n.
Shades of meaning
Fernald has no entry of its own for playfulness; he lists it under wit.
He lists it without comment; the entries above explain its neighbors.