Antonyms of adj unalert

1 sense of unalert

Sense 1
unalert (vs. alert), unwatchful, unvigilant -- (not alert to what is potentially dangerous)

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")
        => 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")
        => fly -- ((British informal) not to be deceived or hoodwinked)
        => heads-up, wide-awake -- (fully alert and watchful; "played heads-up ball")
        => lidless, sleepless -- (always watchful; "to an eye like mine, a lidless watcher of the public weal"- Alfred Tennyson)

Similarity of adj unalert

1 sense of unalert

Sense 1
unalert (vs. alert), unwatchful, unvigilant -- (not alert to what is potentially dangerous)
          Also See-> unwary#1