Ornament Edward found in stream (6)
I believe the answer is:
bedeck
'ornament' is the definition.
(bedecking is a kind of ornamenting)
'edward found in stream' is the wordplay.
'edward' becomes 'ed'.
'found in' is an insertion indicator.
'stream' becomes 'beck' (northern English dialect term for 'stream').
'ed' put into 'beck' is 'BEDECK'.
(Other definitions for bedeck that I've seen before include "Festoon; decorate" , "Adorn, embellish" , "dress" , "Festoon, adorn" , "Lavishly decorate" .)