Fork-tailed bird (7)
I believe the answer is:
swallow
'fork-tailed bird' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for swallow that I've seen before include "One of these does not make a spring" , "Fall for; bird" , "Get down" , "Bird - drink" , "Creature which can go up" .)