The following words are used during daily life at Harrow, and will almost certainly be unfamiliar to newcomers to the School. The origins of many of them have been lost in the mists of time, but new boys adopt them with enthusiasm and they remain a common language among Harrovians and staff of all generations.

• Beak - Teacher (also known as a "master")
  
• Bill or Call-over - A roll call held in each House that boys from the House must attend.
  
• Bill Book - A small blue book published each term providing essential information about all aspects of the School and a calendar of main events, fixtures etc.
  
• Bluer - The dark blue uniform jacket.
  
• Copy - Awarded for 12 send ups or to the top boy in each subject every term. 8 copies win a prize.
  
• Double - Lines on special paper set as a punishment.
  
• Ducker - The swimming pool (in the Sports Centre).
  
• Eccer - Any form of games.
  
• Flannels - School colours for sport. A boy awarded his Flannels for Cricket, Rugby, Football, Harrow Football or for Minor Sports can wear a grey waistcoat with his tails.
  
• Greyers - The grey School trousers.
  
• The Guild - A specially elected group of senior boys who have shown artistic or cultural excellence. They have a distinctive maroon tie and can wear a maroon waistcoat with their tails.
  
• Locking Up - The deadline by which any work or punishments must be handed-in. It is also the time after which pupils may not leave their House without putting their name in the 'signing out' book.
  
• Monitor (School) - School 'prefect'.
  
• Monitor (House) - House 'prefect' (called a Sixth Former or 'priv' in some Houses).
  
• Philathletic Club - The School's top athletes. They can wear a black bow-tie. Commonly called 'The Phil'.
  
• Queue - Times each day to see the House Master to withdraw money, to report send ups and skews, and for other matters of business or concern.
  
• Remove - The second year group at Harrow.
  
• Send Up - A piece of very good work.
  
• Shell - The youngest year group at Harrow.
  
• Shepherd - A boy in the year above whose job it is to look after new Shell boys for their first two weeks.
  
• Skew - Punishment from a beak for poor or incomplete work.
  
• Sunday dress - Tail coat and striped trousers worn on Sundays and other major occasions.
  
• Tolley Up - Permission to work after lights out (only used in a few Houses).
  
• Torpids - House sports team (under 16).
  
• Tosh - A bath or shower.
  
• Trials - Internal School examinations.
  
• Yarder - Outdoor recreation area (also the name of a game played there).
  
• Yearlings - Shell teams or groups.