| on the ball(expression, adjective, idiom, keen, alert) |
| on the lookout(expression, adjective, idiom, keen, restrained) |
| on the qui vive(expression, adjective, idiom, keen, anxious) |
| on the watch(expression, adjective, idiom, ready, alert) |
| on to(expression, adjective, careful, aware, attentive) |
| on toes(expression, adjective, keen, alert, careful) |
| open-eyed(adjective, keen, anxious, alert, careful) |
| plugged in(expression, adjective, careful, aware, attentive) |
| prepared(adjective, ready, alert, careful, cautious) |
| ready(adjective, alert, careful, cautious, attentive) |
| regardful(adjective, careful, knowledgeable, cautious, aware) |
| respectful(adjective, careful, knowledgeable, cautious, aware) |
| see after(expression, adjective, ready, alert, careful) |
| see to(expression, adjective, ready, alert, careful) |
| sensible(adjective, careful, knowledgeable, cautious, aware) |
| sharp(adjective, keen, anxious, alert, careful) |
| sleepless(adjective, keen, anxious, alert, careful) |
| solicitous(adjective, careful, knowledgeable, cautious, aware) |
| suspicious(adjective, restrained, alert, careful, hesitant) |
| thoughtful(adjective, careful, knowledgeable, cautious, aware) |