The Collaborative International Dictionary of English v.0.48:
Sportive \Sport"ive\ (-[i^]v), a. Tending to, engaged in, or provocative of, sport; gay; frolicsome; playful; merry. [1913 Webster] Is it I That drive thee from the sportive court? --Shak. [1913 Webster] -- Sport"ive*ly, adv. -- Sport"ive*ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
sportiveness n 1: lively high-spirited playfulness [syn: friskiness, frolicsomeness, sportiveness]