Kick out swimmer holding ten pence (5)
I believe the answer is:
expel
'kick out' is the definition.
(synonyms)
'swimmer holding ten pence' is the wordplay.
'swimmer' becomes 'eel' (eels swim).
'holding' means one lot of letters goes inside another.
'ten' becomes 'X' (Roman numeral).
'pence' becomes 'p'.
'x'+'p'='xp'
'eel' going around 'xp' is 'EXPEL'.
(Other definitions for expel that I've seen before include "Force to leave" , "Reject" , "Discharge in disgrace" , "Drive out, banish" , "Drive out - eject" .)