A bonus room is a relatively recent term that is mainly used in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is used to describe a large room in a house

House

A house is a building or structure that has the ability to be occupied for dwelling by human beings or other creatures. The term house includes many kinds of different dwellings ranging from rudimentary huts of nomadic tribes to free standing individual structures...

 which could be used as a multi-purpose area. A bonus room, unlike an American bedroom

Bedroom

A bedroom is a private room where people usually sleep for the night or relax during the day.About one third of our lives are spent sleeping and most of the time we are asleep, we are sleeping in a bedroom. To be considered a bedroom the room needs to have bed. Bedrooms can range from really simple...

, does not usually contain a closet

Closet

A closet is a small and enclosed space, a cabinet, or a cupboard in a house or building used for general storage or hanging clothes. A closet for food storage is usually referred to as a pantry...

. A bonus room might be used as a family room

Family room

A family room is an informal, all-purpose room in a house similar to a living room. The family room is designed to be a place where family and guests gather for group recreation like talking, reading, watching TV, and other family activities. Often, the family room is located adjacent to the...

, sewing

Sewing

Sewing is the craft of fastening or attaching objects using stitches made with a needle and thread. Sewing is one of the oldest of the textile arts, arising in the Paleolithic era...

 or hobby

Hobby

A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...

 room, game

Tabletop game

Tabletop game is a general term used to refer to board games, card games, dice games, miniatures wargames, tile-based games and other games that are normally played on a table or other flat surface...

 room, home cinema

Home cinema

Home cinema, also commonly called home theater, are home entertainment set-ups that seek to reproduce a movie theater experience and mood with the help of video and audio equipment in a private home....

, office

Small office/home office

Small office/home office, or SOHO, refers to the category of business or cottage industry which involves from 1 to 10 workers. SOHO can also stand for single office/home office....

, or den. It is sometimes over a garage or in an attic area with partially reduced ceiling height or some other less desirable characteristic. In some areas the term may be used to describe a room that cannot legally be called a bedroom (because of inadequate ceiling height, fire safety features, etc.).

Etymology

One early use of the word is from The New York Times

The New York Times

The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...

in 1991, which described it as "A recent solution to the problem of noisy teen-agers is the enticingly titled bonus room, which is a spare room on the bedroom floor that can be used as a den, television room or guest room."