Deep valley passing through Luxembourg or Germany (5)
I believe the answer is:
gorge
'deep valley' is the definition.
(I've seen this before)
'passing through luxembourg or germany' is the wordplay.
'passing through' indicates a hidden word.
'GORGE' can be found hidden inside 'luxembourg or germany'.
(Other definitions for gorge that I've seen before include "Steep narrow valley" , "Chasm; overeat" , "oesophagus" , "Devour" , "Swallow greedily" .)