by chance 

英汉解释

偶然；意外地

同义词

r. accidentally，haply，incidentally，perchance

反义词

r.   advisedly，deliberately，designedly，intentionally

参考例句

1. I met her quite by chance.
我遇见她完全是偶然的。
2. I am not on this earth by chance. I am here for a purpose.
我并不是偶然的来到这个世上。我是为著一个目的而来。
3. During the First World War, a well-known expert in metals discovered stainless steel by chance.
在第一次世界大战期间，一位有名的金属专家偶然中发现了不锈钢。

英英解释

adv.
  1. in an incidental manner
  2. through chance,
  3. by accident
  4. without advance planning

网络释义

by chance
偶然,碰巧; 偶然，碰巧，意外地; 偶然; 借一次机会;
by any chance
万一，也许; 偶然地; 碰巧;
by some chance
由于某种原因;
Come-by-Chance
卡姆拜钱斯; 卡姆拜钱斯（加拿大）;
by chance
偶然，碰巧;