open-eyed ope·neyed uncommon adjective 1. carefully observant or attentive; on the lookout for possible danger “a policy of open-eyed awareness” “the vigilant eye of the town watch” “there was a watchful dignity in the room” “a watchful parent with a toddler in tow” Synonymsargus-eyedvigilantwakefulwatchful Similaralert WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.