Odd drips around a fast-flowing stream (6)
I believe the answer is:
rapids
'fast-flowing stream' is the definition.
(fast-flowing water)
'odd drips around a' is the wordplay.
'odd' is an anagram indicator.
'around' means one lot of letters goes inside another.
'drips' with letters rearranged gives 'rpids'.
'rpids' going around 'a' is 'RAPIDS'.
(Other definitions for rapids that I've seen before include "Parts of a river where the current is very fast" , "Current hazard" , "Fast-flowing and turbulent part of a river" , "White water area" , "fast flowing water" .)