Fly from a mixed double set (6)
I believe the answer is:
tsetse
'fly' is the definition.
(biting fly found in tropical Africa)
'a mixed double set' is the wordplay.
I cannot really understand how this works, but
an anagram of 'set' is 'tse' which is located in the answer.
The remaining letters 'tse' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'from' acts as a link.
Can you help me to learn more?
(Other definitions for tsetse that I've seen before include "flies" , "Bloodsucking African fly" , "African transmitter" , "fly across Africa" , "source of sleeping sickness" .)