on guard Synonyms

upon one's guard on your guard on one's guard with weather eye open leery on the qui vive wide-awake watchful watch wary wakeful vigilant looking for guarding all ears handling with kid gloves not missing a trick on the watch on the lookout on the alert on one's toes on alert on the ball tutelar sleepless safe defensively defensive circumspect chary cautious careful canny aware awake attentive discreet gingerly regardful ready prudent open-eyed observant mindful insomnious heedful guard guarded alert