Cloak once briefly husband put in Italian river (6)
I believe the answer is:
poncho
'cloak' is the definition.
(I know that poncho is a type of cloak)
'once briefly husband put in italian river' is the wordplay.
'briefly' means to remove the last letter.
'husband' becomes 'h' (abbreviation).
'put in' indicates putting letters inside.
'italian river' becomes 'po' (river in Italy).
'once' with its last letter taken away is 'onc'.
'onc'+'h'='onch'
'onch' going into 'po' is 'PONCHO'.
(Other definitions for poncho that I've seen before include "Type of cloak" , "Garment with slit for the head" , "Blanket-style cloak" , "Mexican cloak" , "Overgarment with hole for head" .)