Flier making a sound turn (4)
I believe the answer is:
tern
'flier' is the definition.
(type of bird)
'a sound turn' is the wordplay.
'a sound' indicates a 'sounds like' (homophone) clue.
'turn' sounds like 'TERN'.
'making' is the link.
(Other definitions for tern that I've seen before include "Three-masted schooner" , "Pay rent for seabird" , "Winger" , "Long-winged aquatic bird" , "Fork-tailed relative of the gull" .)