WordNet sense 1 (waste time; spend one's time idly or inefficiently):

piddle, trifle, piddle away, wanton away

WordNet sense 2 (spend wastefully):

trifle away

WordNet sense 3 (occurring without motivation or provocation):

motiveless, unprovoked

WordNet sense 4 (without motivation):

unmotivated

WordNet sense 5 (become extravagant; indulge (oneself) luxuriously):

luxuriate

WordNet sense 6 (casual and unrestrained in sexual behavior):

easy, light, loose, promiscuous, sluttish

WordNet sense 7 (not chaste):

unchaste