Tower employee brings grouse to diner (9)
I believe the answer is:
beefeater
'tower employee' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'grouse to diner' is the wordplay.
'grouse' becomes 'beef' (synonyms).
'to diner' becomes 'eater' (to dine is to eat a meal).
'beef'+'eater'='BEEFEATER'
'brings' acts as a link.
Can you help me to learn more?
(Other definitions for beefeater that I've seen before include "One might guard" , "Royal servant" , "royal bodyguard" , "Tower of London guard" , "no vegetarian?" .)