| sharp(adjective, adverb, keen, bright, lively) |
| sleepless(adjective, keen, anxious, alert, careful) |
| unsleeping(adjective, keen, anxious, alert, careful) |
| vigilant(adjective, sharp, bright, lively, alert) |
| wakeful(adjective, keen, sharp, anxious, alert) |
| wary(adjective, keen, sharp, bright, lively) |
| with eyes peeled(expression, adjective, idiom, keen, alert) |
| acute(adjective, keen, anxious, alert, careful) |
| advertent |
| agile |
| alive to(expression, adjective, careful, knowledgeable, cautious) |
| all eyes |
| anxious(adjective, keen, alert, careful, attentive) |
| apprehensive(adjective, alert, careful, cautious, aware) |
| au courant(expression, adjective, careful, aware, attentive) |
| be up on(adjective, careful, knowledgeable, cautious, aware) |
| cautious(adjective, keen, alert, careful, knowledgeable) |
| chary(adjective, alert, careful, knowledgeable, cautious) |
| cognizant(adjective, careful, knowledgeable, cautious, aware) |
| concentrated |