River sparkled endlessly, with woman taking dip (7)
I believe the answer is:
shannon
'river' is the definition.
(I've seen this before)
'sparkled endlessly with woman taking dip' is the wordplay.
I cannot quite see how this works, but
'woman' could be 'ann' (woman's name) and 'ann' is found in the answer.
'taking' could be 'on' (eg one taking drugs is 'on' drugs) and 'on' is found in the answer.
The remaining letters 'sh' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for shannon that I've seen before include "Major Irish river" , "Ireland's longest river" , "current in Ireland" , "River in Irish Republic" , "Long-distance runner" .)