Flog directions to students (4)
I believe the answer is:
sell
'flog' is the definition.
(I know that flog can be written as sell)
'directions to students' is the wordplay.
'directions' becomes 'se' (I've seen this in other clues).
'to students' becomes 'll' (an abbreviation for learner driver written twice).
'se'+'ll'='SELL'
(Other definitions for sell that I've seen before include "Peddle" , "Give up for a price" , "Vend, auction off" , "Retail" , "disappointment?" .)