If something happens willy-nilly, it happens even if the people who are involved do not want it to happen.

Both sides were drawn, willy-nilly, into the conflict. 双方都不由自主地被卷进了冲突中。

without any order

She threw her clothes willy-nilly into a drawer. 她把她的衣服乱糟糟地扔进抽屉里。