Australian dame goes back to southern mountains (5)
I believe the answer is:
andes
'mountains' is the definition.
(I've seen this before)
'australian dame goes back to southern' is the wordplay.
'australian' becomes 'A' (common abbreviation).
'back' suggests the final letters.
'to' means one lot of letters go next to another (I've seen this in other clues).
'southern' becomes 'nd' (I can't justify this - if you can you should give a lot more credence to this answer).
The last letters of 'dame goes' are 'es'.
'es' after 'nd' is 'ndes'.
'a'+'ndes'='ANDES'
Can you help me to learn more?
(Other definitions for andes that I've seen before include "Major mountain range" , "Mountains of 6 dn" , "Peak District" , "Mounts" , "danes found in mountains" .)