adjective
paying close attention usually with a view to anticipating approaching danger or opportunity
adopted a policy of watchful waiting
Synonyms: alert, open-eyed, unsleeping, vigilant, wakeful, wide-awake
Related Word: cautious, chary, circumspect, wary; prompt, quick, ready
Idioms: keeping one's eyes peeled ( or open), on the watch ( or lookout)
Contrasted words: careless, heedless, thoughtless; inadvertent; absentminded, abstracted, faraway
Antonyms: unwatchful