Service provided for Highland area (6)
I believe the answer is:
massif
'highland area' is the definition.
'massif' can be an answer for 'area' (I have seen 'mountainous area' mean 'massif' so perhaps 'area' could also mean 'massif'). I am not sure about the 'highland' bit.
'service provided' is the wordplay.
'service' becomes 'mass' (I've seen this in other clues).
'provided' becomes 'if'.
'mass'+'if'='MASSIF'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for massif that I've seen before include "huge piece of crust" , "Mountain block" , "Extensive raised area" , "French mountain range" , "Compact group of mountains" .)