Continental river horse perhaps? Sounds like it (5)
I believe the answer is:
rhone
'continental river' is the definition.
(European river)
'horse perhaps? sounds like it' is the wordplay.
'horse perhaps?' becomes 'roan' (roan can mean a multi-coloured animal eg a horse).
'sounds like it' indicates a 'sounds like' (homophone) clue.
'roan' is a homophone of 'RHONE'.
(Other definitions for rhone that I've seen before include "River at Lyons" , "Major French river, rising in Switzerland" , "wine-producing area" , "French river from Alps to Mediterranean" , "French flower" .)