Formal:
* Mon maître: This is the most formal and traditional way to say "my master." It is usually used when referring to someone who holds a position of authority or expertise, such as a teacher, mentor, or employer.
Informal:
* Mon patron: This means "my boss" and is a more casual way to refer to someone who is your master in a professional sense.
* Mon chef: This means "my chief" and is a more informal way to refer to someone who is in charge of you, such as a manager or supervisor.
Other options:
* Mon seigneur: This is a very old-fashioned and formal way to refer to a lord or master. It is rarely used in modern French.
* Mon supérieur: This means "my superior" and is a more neutral way to refer to someone who is in charge of you.
It is important to note that the word "master" can have negative connotations in French, as it can be associated with slavery and oppression. If you are referring to someone who you consider to be your master in a negative sense, it would be best to use a different word or phrase.
In general, it is best to avoid using the word "master" in French, as it can be easily misunderstood. If you are unsure of how to refer to someone who you consider to be your master, it is always best to use a more neutral term.