vigilant
adjectiveOn the alert, as for danger or error; watchful. synonym: careful.
Watchful, as one who watches during the hours for sleep; ever awake and on the alert; attentive to discover and avoid danger, or to provide for safety; circumspect; cautious; wary.
Indicating vigilance.
Synonyms 1. Wakeful, etc. See
Attentive to discover and avoid danger, or to provide for safety; wakeful; watchful; circumspect; wary.
adjectivecarefully observant or attentive; on the lookout for possible danger