vigilant 8 antonyms and opposites of vigilant. Adj — Watchful and alert, especially for danger, trouble, or wrongdoing. Synonyms for vigilant heedful hip on guard on the lookout on the watch on watch wakeful woke Antonyms for vigilant complacent heedless oblivious unalert unaware unprepared unwary unwitting ← Back to the full definition of vigilant
