The most common and most likely answer to this crossword clue is the 7 letter word HIMSELF
H
I
M
S
E
L
F
Buddy explains!
The straight part
We know that "Master" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case master = himself.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HIMSELF mean?
HIMSELF pronoun- (reflexive pronoun) Him; the male object of a verb or preposition that also appears as the subject
- He; used as an intensifier, often to emphasize that the referent is the exclusive participant in the predicate
- The subject or non-reflexive object of a predicate; he himself.
- The subject or non-reflexive object of a predicate; he (used of upper-class gentlemen, or sarcastically, of men who imagine themselves to be more important than others)