Heedless (6)
'heedless' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for unwary that I've seen before include "Not cautious" , "Incautious and unprepared for danger" , "Off guard" , "Not alert or suspicious" , "Hasty" .)
'heedless' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for reckless that I've seen before include "Careless, rash" , "Wildly incautious" , "not responsible" , "Utterly unconcerned for the consequences" , "Devil-may-care" .)