One keen on deserts is most erratic, moving out of south (10)
I believe the answer is:
meritocrat
'one keen on deserts is most' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'erratic moving out of south' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is present in the answer.
an anagram of 'erratic' is 'eritcra' which is present in the remaining letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for meritocrat that I've seen is " Ruler chosen for excellence".)