Retire an eccentric old family servant (8)
I believe the answer is:
Here is my best explanation:
'old family servant' is the definition.
(I've seen this before)
'retire an eccentric' is the subsidiary indication.
'eccentric' indicates anagramming the letters.
'retirean' is an anagram of 'retainer'.
(Other definitions for retainer that I've seen before include "Fee; long-term servant", "Fee paid to book the services of someone", "Servant; fee", "Advance fee; servant", "Holding fee or faithful old servant", "A down payment or an old servant", "money to be paid in advance", "Family servant; barrister's fee", "Long-term servant" and "Fee paid for first option - old family servant".)