River to cross with some style, one fancies (4)
I believe the answer is:
styx
'river' is the definition.
(mythical river)
'cross with some style one fancies' is the wordplay.
I cannot really understand how this works, but
'cross' could be 'x' (an X is a cross) and 'x' is found in the answer.
The remaining letters 'sty' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for styx that I've seen before include "River crossed at death" , "Mythological river in Hades" , "River Charon rowed on" , "'River of Hate' in Hades" , "classical stream" .)