n.[U]

1. 【物】重力；引力；地心吸力
   The stone rolled down the hill by gravity.

   石头在重力作用下向山下滚去。

2. 重（量）
3. 严重性；危险性；重大
   She does not know the gravity of her illness.

   她不知道自己病情严重。

4. 严肃；庄严；认真
   He could hardly keep his gravity.

   他忍不住要笑出来。

5. 低沉

n.

1. Physics  the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.
   ▸the degree of intensity of this, measured by acceleration.
2. extreme importance; seriousness.
   ▸solemnity of manner.