unknown

US /ʌnˈnoʊn/
UK /ʌnˈnoʊn/
"unknown" picture
1.

未知的, 不熟悉的

not known or familiar

:
The cause of the accident is still unknown.
事故原因仍然不明
She ventured into unknown territory.
她冒险进入了未知的领域。
1.

未知数, 未知事物

an unknown person or thing

:
The letter was sent by an unknown.
这封信是由一个不知名的人寄来的。
We are dealing with too many unknowns in this equation.
我们正在处理这个方程中太多的未知数