Could his intelligence encourage a master? (7)
I believe the answer is:
egghead
'could his intelligence' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'encourage a master?' is the wordplay.
'encourage' becomes 'egg'.
'a master?' becomes 'head' (master is a kind of head).
'egg'+'head'='EGGHEAD'
Can you help me to learn more?
(Other definitions for egghead that I've seen before include "An intellectual (inf.)" , "brain" , "Very academic person" , "Brainiac" , "Intellectual (sl.)" .)