n.

1. 巨大，广大[U]
2. 重大，重要[U]
   No one comprehended the magnitude of the problem then.

   当时无人认识到这一问题的严重性。

3. 量；大小；强度；音量[U]
   It is difficult to imagine the magnitude of the universe.

   宇宙的广大很难想像。

4. 【天】星等（指星的亮度）[C]
   a star of the second magnitude

   第二星等的一颗星

5. 【地】震级[C]
   A giant earthquake registering 9.1 magnitude hit California, causing the death of several thousand people.

   一个震度达9.1级的大地震袭击加州， 造成数千人的死亡。

n.

1. great size, extent, or importance.
2. size:
   electorates of less than average magnitude.
3. Astronomy  the brightness of a star, as represented by a number on a logarithmic scale.