As chairman, did he master the opposition leader? (3)
I believe the answer is:
mao
'as chairman did he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'master the opposition leader?' is the wordplay.
'master' becomes 'ma'.
'leader?' indicates taking the first letters (I've seen 'leaders' mean this).
The initial letter of 'opposition' is 'o'.
'ma'+'o'='MAO'
Can you help me to learn more?
(Other definitions for mao that I've seen before include "Communist leader of China" , "Red" , "Eastern leader" , "- Zedong, Chinese communist leader" , "Former Chinese Chairman" .)