unknown/ˌʌn'nəʊn $ -'noʊn/

a. not known or not famous

a. 未知的，不为人知的；不出名的：[unknown to sb] His identity is still unknown to me. 他的身份我仍然不清楚。

◇an unknown actor 不出名的演员

构词un- + known

常犯错误

✗ His purpose is unknown by her.

✓ His purpose is unknown to her. 她不知道他的目的。