by a chance

基本解释

Her life was changed by a chance meeting with her former art master a few years ago.
她的生活因几年前同她以前的美术老师的偶遇改变了。
A game, usually played for money or stakes, in which the winner is determined by a chance event, as by drawing numbers or throwing dice.
靠运气定胜负的比赛：一种常为钱或赌注而进行的比赛，比赛中获胜者全靠机会决定，一般采用抽签或掷骰子的方式。
But by a chance, Pip helped a convict; he gave much food to him.
但是一个偶然的机会，他帮助了一个囚犯，给了他很多食物。

Blinded by a meaningless imperfection and an impossible goal, Aylmer had thrown away her life and with it his chance for happiness.
If the land isn't taken up by large oligarchies life slaveholding class--then the small guy has a chance.
如果土地没有被大的垄断方占有,奴隶阶级,弱小的一方就仍会有希望
耶鲁公开课 - 美国内战与重建课程节选
Now, if you are standing there with your -- by the way the first three rows have a chance of hitting each other.
现在,如果你站在那里用你的 --,顺便提一下前三排有机会互相攻击
耶鲁公开课 - 古希腊历史简介课程节选

It plays an important social role by offering a chance for self-expression in a communal setting.
UNESCO: Culture