Tried working, exhausted (5)
I believe the answer is:
tired
'exhausted' is the definition.
(exhausted can mean very tired)
'tried working' is the wordplay.
'working' is an anagram indicator.
'tried' is an anagram of 'TIRED'.
(Other definitions for tired that I've seen before include "Done in" , "knackered" , "Drowsy" , "Physically or mentally weary" , "Ready to drop" .)