Final goal bagged by tall lad, netting on the spin (3-3)
I believe the answer is:
end-all
'final goal' is the definition.
(I've seen this in another clue)
'bagged by tall lad netting on the spin' is the wordplay.
'bagged by' indicates the answer is hidden within the clue (the solution is bagged up or contained by the clue).
'the spin' is a reversal indicator.
'lladne' is hidden within 'tall lad netting on'.
'lladne' reversed gives 'END-ALL'.
(Other definitions for end-all that I've seen before include "Ultimate aim" , "Ultimate purpose or justification" , "It finishes everything" , "Ultimate goal" .)