Stuff in deep valley (5)
I believe the answer is:
gorge
I believe this is a double definition.
'stuff' is the first definition.
('gorge' can be a synonym of 'stuff')
'deep valley' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for gorge that I've seen before include "not fast" , "Eat greedily" , "Ravine; glut" , "Swallow greedily" , "Gobble" .)