New U-boat initially holed in a north German route (8)
I believe the answer is:
autobahn
'german route' is the definition.
'autobahn' can be an answer for 'route' (autobahn is a kind of route). I am not sure about the 'german' bit.
'new u-boat initially holed in a north' is the wordplay.
'new' is an anagram indicator.
'initially' suggests taking the first letters.
'in' indicates putting letters inside.
'north' becomes 'n' (synonyms).
The initial letter of 'holed' is 'h'.
'u'+'boat'+'h'='uboath'
'uboath' anagrammed gives 'utobah'.
'a'+'n'='an'
'utobah' placed into 'an' is 'AUTOBAHN'.
Can you help me to learn more?
(Other definitions for autobahn that I've seen before include "way abroad" , "Great way" , "It takes continental drivers" , "overseas route" , "expressway" .)