She dressed provocatively and flirted wantonly with strangers at the party.

wantonly 是形容词 wanton 的副词形式。wanton 本义是"任性的、放纵的"，常带有贬义，指行为不受约束、不顾后果。wantonly 表示"肆意地、放纵地"做某事，通常指轻浮或不当的行为。