Rule in wet conditions, say (5)
I believe the answer is:
reign
This clue could be a double definition.
'rule' is the first definition.
(I know that rule can be written as reign)
'wet conditions say' is the second definition.
'reign' can be an answer for 'say' (thesaurus). I'm not sure about the 'wet conditions' bit.
'in' is the link.
Can you help me to learn more?
(Other definitions for reign that I've seen before include "Have sovereign power" , "Period during which someone is dominant" , "Be champion" , "Sit on a throne" , "Rule as king or queen" .)