observation in WordNet English dictionary

1. the act of noticing or paying attention
   "he escaped the notice of the police"
   notice  observation  observance 
   
2. the act of observing; taking a patient look
   observation  observance  watching 
   
3. the act of making and recording a measurement
   observation 
   
4. facts learned by observing
   "he reported his observations to the mayor"
   observation 
   
5. a remark expressing careful consideration
   observation  reflection  reflexion