British sailors occupy a border town in Holland (6)
I believe the answer is:
arnhem
'town in holland' is the definition.
The definition suggests a singular noun which matches the answer.
'british sailors occupy a border' is the wordplay.
I cannot really understand how this works, but
'sailors' could be 'rn' (abbreviation for Royal Navy) and 'rn' is found in the answer.
'a' is within the answer.
'border' could be 'hem' (I've seen this before) and 'hem' is located in the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for arnhem that I've seen before include "Site of 1944 battle" , "WW2 battle" , "Location of battle" , "Second World War battle" , "Netherlands scene of 1944 battle" .)