Oil producer in plant entertaining our relatives (8)
I believe the answer is:
rapeseed
'oil producer' is the definition.
(I've seen this before)
'plant entertaining our relatives' is the wordplay.
I cannot quite see how this works, but
'plant' could be 'seed' (seed plant is a kind of plant) and 'seed' is found in the answer.
The remaining letters 'rape' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for rapeseed that I've seen before include "Part of plant yielding oil" , "Oil-rich crop" , "Oil producer" , "Source of cooking oil" .)