Definition: having the ability to notice slight differences
Part of Speech: Adjective
Synonym(s): alert, intent
Antonym(s): stupid, ignorant
1. The detective’s keen observational skills led him to the clue that solved the murder case.
2. After travelling throughout the world, I acquired a keen ability to recognize distinct accents.
3. Because the cat had keen eyesight, it was able to notice the bird’s movements without moving its head.