Call set up including one who gave noble service (8)
I believe the answer is:
liegeman
'call set up including one who gave noble service' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'call set up including one' is the wordplay.
'call' becomes 'name' (as in calling or naming someone something).
'set' becomes 'gel' (both can mean to harden).
'up' is a reversal indicator (in down clue: letters go upwards).
'including' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'name'+'gel'='namegel'
'namegel' reversed gives 'legeman'.
'legeman' enclosing 'i' is 'LIEGEMAN'.
Can you help me to learn more?
(Other definitions for liegeman that I've seen before include "A loyal person" , "Person serving lord" , "Loyal follower" , "Vassal, subject" .)