Water found in edges of Charlie's hat (6)
I believe the answer is:
cloche
'hat' is the definition.
(cloche is a kind of hat)
'water found in edges of charlie's' is the wordplay.
'water' becomes 'loch' (a loch is a body of water).
'found in' is an insertion indicator.
'edges of' means to remove the middle letters.
'charlie' with its centre taken out is 'ce'.
'loch' placed inside 'ce' is 'CLOCHE'.
(Other definitions for cloche that I've seen before include "seedlings may need it" , "protection for young stock?" , "useful in the garden" , "Protective covering for plants from frost" , "Nursery plant protection" .)