Overhear a snag (5)
I believe the answer is:
catch
I believe this is a double definition.
'overhear' is the first definition.
(synonyms)
'a snag' is the second definition.
(I've seen this in another clue)
(Other definitions for catch that I've seen before include "Arrest" , "It's taken by a fielder to dismiss a player in baseball and cricket" , "Fastener on door or window" , "Take hold of" , "Apprehend - funny song" .)