Old and very unpopular American covered beat (9)
I believe the answer is:
exhausted
'beat' is the definition.
(I've seen this in another clue)
'old and very unpopular american covered' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'and' is a charade indicator (letters next to each other).
'very unpopular' becomes 'hated' (someone hated is very unpopular).
'american' becomes 'us' (abbreviation for United States).
'covered' means one lot of letters goes inside another.
'ex'+'hated'='exhated'
'exhated' placed around 'us' is 'EXHAUSTED'.
(Other definitions for exhausted that I've seen before include "All in, really tired" , "ready for bed" , "Drained of strength" , "Worn out" , "Dead-beat" .)