Identical twins swat away insect furiously, which makes it move faster (8)
I believe the answer is:
tailwind
'identical twins swat' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'away insect furiously which makes it move faster' is the wordplay.
I cannot quite understand how this works, but
'away' could be 'a' (abbreviation as used in sports fixtures) and 'a' is present in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found within the answer.
'move' could be 'wind' (winding is a kind of moving) and 'wind' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tailwind that I've seen before include "Favourable air current" , "Blow to back" , "It increases one's (ground)speed" , "Boost for one running" .)