Time runs out for swimmer (5)
I believe the answer is:
trout
'swimmer' is the definition.
(trout is a kind of aquatic vertebrate)
'time runs out' is the wordplay.
'time' becomes 't' (abbreviation).
'runs' becomes 'r' (cricket abbreviation).
't'+'r'+'out'='TROUT'
'for' acts as a link.
(Other definitions for trout that I've seen before include "one of a noted quintet" , "Game fish related to salmon" , "tickled to death?" , "Fish (associated with Schubert?)" , "one may be hooked" .)