Fish served by maid primarily in reception room (6)
I believe the answer is:
salmon
'fish' is the definition.
(salmon is a kind of fish)
'maid primarily in reception room' is the wordplay.
'primarily' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'reception room' becomes 'salon' (I've seen this before).
The first letter of 'maid' is 'm'.
'm' going within 'salon' is 'SALMON'.
'served by' acts as a link.
(Other definitions for salmon that I've seen before include "high-jumper" , "Pink-fleshed fish" , "Sockeye, for example" , "See 3" , "Fish; pink colour" .)