Here are some common possibilities:
* Postgraduate: This is a common abbreviation for someone who is pursuing a master's degree or doctorate.
* Paying Guest: This is a term used in India and some other countries to refer to a person who rents a room in a private home.
* Parental Guidance: This is a rating system used by the Motion Picture Association of America to indicate that a movie is suitable for children with parental guidance.
* Propylene Glycol: This is a chemical compound commonly used in food and cosmetics.
Can you give me more information about what you are looking for? That will help me determine the correct full name for "PG".