1. the action or process of watching someone or something carefully
2. a remark, statement, or comment based on something one has seen, heard, or noticed
3. the ability to notice things

Examples

• The scientist made careful observations of the animal’s behavior.
• Her observation about the weather proved to be correct.
• The security guard kept the building under observation all night.
• He shared an interesting observation about human nature.
• The doctor’s observations helped diagnose the patient’s condition.
• Powers of observation are essential for a detective.
• The research was based on direct observation of the phenomenon.