Thrash exhausted American (4)
I believe the answer is:
beat
This clue could be a double definition.
'thrash' is the first definition.
(synonyms)
'exhausted american' is the second definition.
'beat' can be an answer for 'exhausted' (I've seen this in other clues). I'm not certain of the 'american' bit.
Can you help me to learn more?
(Other definitions for beat that I've seen before include "tired" , "Defeat; throb" , "cane" , "buffet" , "Come out better than in a competition" .)