| unsleeping(adjective, keen, alert, careful, disturbed) |
| absorbed(adjective, set, attention, deep, fixed) |
| all ears(expression, adjective, sharp, bright, lively) |
| apprehensive(adjective, upset, cool, excited, ready) |
| assiduous(adjective, considerate, cautious, responsive, helpful) |
| conscientious(adjective, alert, careful, caring, thoughtful) |
| diplomatic(adjective, cautious, tactful, circumspect) |
| discerning(adjective, understanding, cool, reasonable, keen) |
| hawk-eyed |
| insomniac(adjective, careful, restless, disturbed, awake) |
| on the job(expression, adjective, idiom, keen, sharp) |
| perceptive(adjective, understanding, cool, sharp, bright) |
| prompt(adjective, responsive, early) |
| rapt(adjective, set, attention, deep, fixed) |
| active(sharp, bright, lively, alert, aware) |
| cagey(adjective, sharp, smart, bright, sensible) |
| concentrating(adjective, set, determined, deep, caring) |
| engrossed(adjective, set, determined, deep, fixed) |
| exacting(adjective, cautious, wary, vigilant) |
| fastidious(adjective, cautious, suspicious, wary, vigilant) |