Youngster, a learner unqualified (5)
I believe the answer is:
Here is my best explanation:
'unqualified' is the definition.
('total' can be a synonym of 'unqualified')
'youngster a learner' is the subsidiary indication.
'youngster' becomes 'tot' (tot is a kind of youngster**).
'learner' becomes 'l'.
(Other definitions for total that I've seen before include "Full, entire amount", "Sum or aggregate", "Aggregate, sum", "Entire amount", "Comprising the whole", "Aggregate amount", "Absolute, complete", "Whole amount", "Amount to; complete" and "Complete, entire amount".)