Chance of money abroad lifted doctor (6)
I believe the answer is:
Here is my best explanation:
'chance' is the definition.
('random' can be similar in meaning to 'chance')
'money abroad lifted doctor' is the subsidiary indication.
'money abroad' becomes 'rand' (currency of South Africa).
'lifted' says the letters should be written in reverse (going up in down clue).
'doctor' becomes 'mo' (**).
'mo' backwards is 'om'.
'of' is the link.
(Other definitions for random that I've seen before include "Occurring by chance, no fixed pattern", "Happening by chance, haphazard", "Indiscriminate", "Governed by chance", "Happening without method", "Haphazard, occuring by chance", "Disorganised", "Lacking regularity", "Without pattern" and "Chance, haphazard".)