v.
   - notice; perceive. 
▸watch attentively.
 ▸detect in the course of a scientific study.
 - say; remark:
 ‘It's chilly,’ she observed.
 - fulfil or comply with (an obligation).
 
 
  Derivative
  
    - observable adj.
  - observably adv.
  - observer n.
 
   
  Etymology
  ME: from OFr. observer, from L. observare ‘to watch’.