a.

1. 不知道的；未知的；陌生的；默默無聞的[（+to）]
   We bought a drawing by an unknown artist.

   我們買了一幅某個不出名的畫家所作的畫。

n.

1. 默默無聞的人；未知的事物[C][the S]
   The author had been an unknown until he published his recent book.

   這位作家一直是個默默無聞的人，直到最近出版了他的一本書。

adj.

n.