Definition of "Master"

Master

noun
plural Masters
1. Prepended to a boy's name or surname as a (now somewhat formal) form of address.
  Quotations
  "I'm terribly sorry, Master Luke," apologized the droid.
  1995, Barbara Hambly, Children of the Jedi, page 81
2. A religious teacher, often as an honorific title.
3. The title of the head of certain colleges and schools.
4. A master's degree.
5. A person holding a master's degree, as a title.
6. The title of the eldest son of a Scots lord.
7. The owner of a slave, in some literature.
8. (BDSM) Used as the title of a dominant.
proper noun
1. (Wicca) One of the triune gods of the Horned God in Wicca alongside the Father and Sage and representing a boy or a young man
  Quotations
  ...and our Lord as Master, Father, and Sage.
  2002, A. J. Drew, Wicca for Couples: Making Magick Together, page 89
  In respect to our Lord (God), these are the less known Master, Father, and Sage.
  2003, A. J. Drew, Patricia Telesco, God/Goddess: Exploring and Celebrating the Two Sides of Wiccan Deity, page 38
  Master of the Seasons of the Year, I call upon you and ask you to be here with me in this, my ritual.
  2009, Debbe Tompkins, Witch School: Living the Wiccan Life, page 18
2. (banking) Mastercard