playfulness C2+

/ˈpleɪfəlnəs/ a lighthearted, fun-loving quality

playfellow C2+

/ˈpleɪˌfɛloʊ/ a companion in play; a playmate

plaything C2+

/ˈpleɪˌθɪŋ/ a toy, or a person or thing treated as an object of amusement