Letter attached to old poem about Dubai for example (7)
I believe the answer is:
emirate
'dubai for example' is the definition.
(Dubai is an emirate of the United Arab Emirates)
'letter attached to old poem about' is the wordplay.
'letter' becomes 'eta' (eta is a kind of letter of the alphabet).
'attached to' means one lot of letters go next to another.
'old poem' becomes 'rime' (archaic spelling of 'rhyme').
'about' is a reversal indicator.
'eta'+'rime'='etarime'
'etarime' in reverse letter order is 'EMIRATE'.
(Other definitions for emirate that I've seen before include "Team ire (anag.)" , "Arab state" , "Arab territory" , "Arab domain" , "Independent Islamic state" .)