late 14c., "subject to or produced by chance," from Middle French casuel (15c.), from Late Latin casualis "by chance," from Latin casus "chance, occasion, opportunity; accident, event" (see case (n.1)).
Of persons, in the sense of "not to be depended on, unmethodical," it is attested from 1883; meaning "showing lack of interest" is from 1916. Of clothes, "informal," from 1939. Related: Casually.
权威例句
1. I was wrong about it being a casual meeting.
我误以为这是个非正式会议。
2. A sharp dresser, Wyatt is never seen in casual clothes.
怀亚特衣着入时,从未有人见过他穿便装。
3. Lust now seems to be associated with casual sex and loose morals.
色欲如今似乎与性生活随便和道德放纵联系在一起了。
4. Garland tried to appear casual, but he couldn't conquer his unease.