Rumba dancing country once (5)
I believe the answer is:
burma
'country once' is the definition.
I can't tell whether this defines the answer.
'rumba dancing' is the wordplay.
'dancing' indicates anagramming the letters.
'rumba' with letters rearranged gives 'BURMA'.
Can you help me to learn more?
(Other definitions for burma that I've seen before include "Country of SE Asia" , "Old name for Myanmar" , "It's now called Myanmar" , "Myanmar, formerly" , "SE Asian country" .)