1. to watch carefully; to notice or see
2. to follow or obey a rule, law, or custom
3. to celebrate or acknowledge a holiday or special occasion

Examples

• The scientist observes the behavior of the animals in their natural habitat.
• She observes all traffic laws when driving.
• Our family observes Thanksgiving every year with a big dinner.
• The teacher observes that students learn better with hands-on activities.
• He carefully observes the stars through his telescope.
• The company observes a strict dress code policy.
• The detective observes every detail at the crime scene.