| active(adjective, keen, sharp, smart, energetic) |
| all there(expression, smart, bright, skillful, brainy) |
| animate(adjective, strong, intense, energetic, powerful) |
| animated(adjective, strong, intense, energetic, powerful) |
| apprehensive(adjective, cool, significant, intelligent, brilliant) |
| arch |
| argute(sharp, smart, intelligent, clever, astute) |
| astucious(sharp, smart, intelligent, clever, astute) |
| attentive |
| au fait(expression, adjective, familiar, informed, well-informed) |
| autodidactic(adjective, learner) |
| awake(adjective, cool, significant, intelligent, brilliant) |
| biting |
| breezy |
| brisk |
| cagey(sharp, smart, bright, intelligent, clever) |
| careful(smart, sensible, wise, shrewd, clever) |
| caustic(adjective, strong, keen, sharp, intense) |
| cautious(smart, sensible, wise, shrewd, clever) |
| circumspect(smart, sensible, wise, shrewd, clever) |