n.

1. 观察；观测；观察力[U][C]
   He is a man of little observation.

   他是个观察力极差的人。

2. （观察后发表的）言论，意见[C][（+on/about）][+（that）]
   I have a few observations to make on your conduct.

   我对你的行为有一些看法要说。

3. 察觉；注意，监视[U]
   They decided to put him under observation.

   他们决定监视他。

4. 观察（或观测）资料（或报告）[P1]
   He will publish his observations on the social life of these primitive tribes.

   他将公布他对那些原始部落的社会生活观察所得的资料。

n.

1. the action or process of closely observing or monitoring.
2. the ability to notice significant details.
3. the taking of the sun's or another celestial body's altitude to find a latitude or longitude.
4. a comment based on something one has seen, heard, or noticed.