Polish rejected by mother country (5)
I believe the answer is:
burma
'country' is the definition.
(Burma is an example)
'polish rejected by mother' is the wordplay.
'polish' becomes 'rub' (polish meaning rub to make shiny**).
'rejected' says the letters should be written in reverse.
'by' says to put letters next to each other.
'mother' becomes 'ma' (ma is a kind of mother).
'rub' back-to-front is 'bur'.
'bur'+'ma'='BURMA'
(Other definitions for burma that I've seen before include "Country of SE Asia" , "Union of Myanmar" , "Another name for Myanmar" , "Country whose name was changed to Myanmar in 1989" , "Rumba (anag)" .)