Mad liar maybe, and a master of craft (7)
I believe the answer is:
admiral
'a master of craft' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'mad liar maybe' is the wordplay.
'maybe' is an anagram indicator.
'mad'+'liar'='madliar'
'madliar' anagrammed gives 'ADMIRAL'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for admiral that I've seen before include "Naval high-up" , "Powerful sailor" , "Naval chief" , "Navy rank" , "Brightly coloured butterfly" .)