observant
UK: əbˈzɜːvənt | US: əbˈzɜːrvənt
adj. quick to notice or perceive things; attentive
adj. adhering strictly to rules or traditions
n. a person who observes carefully
The word "observant" emerged in Late Middle English (15th century) from the Latin observant-, the present participle stem of observare. It originally described someone who diligently followed religious or social rules. Over time, it broadened to describe general attentiveness. The suffix -ant reinforces the active quality of observing, making it both descriptive and dynamic.
The observant detective noticed the tiny scratch on the door.
She is highly observant of cultural etiquette when traveling.
Only the most observant viewers spotted the hidden clue in the film.
As an observant Jew, he strictly follows dietary laws.
The teacher praised the observant student for catching the error in the textbook.