Or third degree in Freemasonry. The funny thing is that it isn't actually a Master Mason degree, not in the sense that the previous two degrees corresponded with degrees granted in guilds. The other two are pretty straightforward: that of an apprentice beginning his career, that of a Fellowcraft or Journeyman refining his knowledge. In the other degrees it's said that the Master Mason degree corresponds to a sort of masterly retirement and that entered apprentice and fellowcraft correspond to youth and adult hood. But that's not really how it is. Instead, the degree of Master is in my opinion a continuation of the Fellowcraft degree. The degree of Master is not really given, but a drama communicates the idea that the key to the Master degree was lost and the Temple, the allegory for the candidate's personal work on himself , remained unfinished. Therefore, the person who is initiated into the Master degree has to do what was sort of indicated in the Fellowcraft degree: leave the temple and go out on his own to find the truth. The process of initiation ends with the candidate becoming an emancipated individual, someone who has to find his own truth without the benefit of a temple system to help him out.
This is why there are so many degrees above that of Master Mason. And why there are more masters than there would be if it was truly a degree only given to people who were older than just in their prime of life.