Antonyms of adj vigilant

1 sense of vigilant

Sense 1
argus-eyed, open-eyed, vigilant, wakeful -- (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")

INDIRECT (VIA alert) -> unalert, unwatchful, unvigilant -- (not alert to what is potentially dangerous)

Similarity of adj vigilant

1 sense of vigilant

Sense 1
argus-eyed, open-eyed, vigilant, wakeful -- (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")
       => alert (vs. unalert), watchful -- (engaged in or accustomed to close observation; "caught by a couple of alert cops"; "alert enough to spot the opportunity when it came"; "constantly alert and vigilant, like a sentinel on duty")