The German might backtrack and block one using Flemish bond (8)
I believe the answer is:
redbrick
'one using flemish bond' is the definition.
The definition suggests a singular noun which matches the answer.
'the german might backtrack and block' is the wordplay.
I cannot really see how this works, but
'german' could be 'd' (abbreviation for Deutschland ie Germany) and 'd' is located in the answer.
'block' could be 'brick' and 'brick' is located in the answer.
The remaining letters 're' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for redbrick that I've seen before include "not Oxbridge material" , "Non-Oxbridge" , "Newer (university)" , "Class of university" , "Style of university" .)