| a. | 1. | Extremely observant; watchful; sharp-sighted. |
| Adj. | 1. | argus-eyed - having very keen vision; "quick-sighted as a cat" |
| 2. | argus-eyed - 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" |