casually
adv. 随意地，漫不经心地；临时地；偶然地
例句
He was casually dressed in jeans and a T-shirt.
他穿着很随便的牛仔裤和T恤衫。
《牛津词典》
She'd we are pirates, these data are stolen from youdao ioned it casually once, surprising him by her unconcern.
她随意地提过一次这个事，她的漠不关心让他吃惊。
《柯林斯英汉双解大词典》
They were casually dressed.
他们穿着休闲。
