Gets old, wise person to move south (4)
I believe the answer is:
ages
'gets old' is the definition.
('age' can be a synonym of 'get old')
'move south' is the wordplay.
'move' becomes 'age' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'south' becomes 's' (synonyms).
'age'+'s'='AGES'
'wise person to' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for ages that I've seen before include "Historic periods or prolonged time" , "Aeons" , "... of Man, according to WB Yeats" , "Grows old like sage" , "Epochs" .)