| vigilant(adjective, feature, characteristic, sharp, bright) |
| observant(adjective, feature, characteristic, keen, detail) |
| alert(adjective, feature, characteristic, keen, sharp) |
| watchful(adjective, feature, characteristic, keen, sharp) |
| attentive(adjective, feature, characteristic, keen, detail) |
| aware(adjective, feature, characteristic, keen, detail) |
| heedful(adjective, feature, characteristic, sharp, bright) |
| wakeful(adjective, keen, anxious, alert, careful) |
| regardful(adjective, feature, characteristic, detail) |
| surprised(verb, amazed) |
| wary(adjective, keen, sharp, alert, careful) |
| wide-awake(adjective, keen, anxious, alert, careful) |
| agog(keen, anxious, alert, careful, cautious) |
| argus-eyed |
| astounded |
| careful(adjective, keen, sharp, alert, cautious) |
| intent(adjective, feature, characteristic, detail) |
| on the ball(expression, adjective, idiom, keen, alert) |
| perceptive(adjective, alert, watchful) |
| active(adjective, alert) |