Attempt to send fliers back (4)
I believe the answer is:
stab
'attempt to' is the definition.
(I've seen this before)
'fliers back' is the wordplay.
'fliers' becomes 'bats' (things that fly).
'back' shows that the letters should be reversed in order.
'bats' in reverse letter order is 'STAB'.
'send' is the link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for stab that I've seen before include "Inflict wound with knife" , "Try - skewer" , "Attack with a knife" , "Attack with a dagger" , "Plunge knife into" .)