argus-eyed vs vigilant

argus-eyed and vigilant both are adjectives.

Word	Noun	Adjective	Verb	Adverb
argus-eyed	No	Yes	No	No
vigilant	No	Yes	No	No

As adjectives, argus-eyed and vigilant are synonyms defined as:

argus-eyed and vigilant: carefully observant or attentive; on the lookout for possible danger

Other synonyms of argus-eyed include open-eyed, wakeful, watchful.

argus-eyed (adjective)	vigilant (adjective)
carefully observant or attentive; on the lookout for possible danger	carefully observant or attentive; on the lookout for possible danger
having very keen vision