A more thorough explanation:

Definition: A vacation barrister is a type of lawyer in England or Northern Ireland who has been admitted to plead at the bar and argue cases in superior courts. They are also known as barristers and are part of the legal profession that is divided into barristers and solicitors in many Commonwealth nations.

Examples: A vacation barrister is a newly called barrister who must attend inn-of-court functions during the long vacation for at least three years. They are not allowed to plead from within the bar like a Queen's Counsel or a serjeant-at-law.

Explanation: The example illustrates that a vacation barrister is a type of barrister who is newly called to the bar and must attend inn-of-court functions during the long vacation. They are not allowed to plead from within the bar like other types of barristers. This definition and example are written in simple English that a high school student can understand.