Stout stem (7)
I believe the answer is:
staunch
This clue is a double definition.
'stout' is the first definition.
(I've seen this before)
'stem' is the second definition.
(I know that stem can be written as staunch)
(Other definitions for staunch that I've seen before include "Loyal; restrict (a flow of blood)" , "Firm; stem" , "Hearty" , "Very loyal; stop (a flow of blood)" , "Stay - faithful" .)