Background

When laying out floor plans for buildings, designers sometimes are unable to avoid small “left over” spaces which cannot be put to practical use. This problem is particularly severe in buildings with angular

Angle

In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...

 or curvilinear geometry

Geometry

Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....

. These spaces are called “spear closets” because, due to their size and shape, they cannot serve any practical purpose other than possibly to store one’s spears.

Current usage

Since, in the modern world, few people actually own spear

Spear

A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head.The head may be simply the sharpened end of the shaft itself, as is the case with bamboo spears, or it may be made of a more durable material fastened to the shaft, such as flint, obsidian, iron, steel or...

s and keep them at home, the term is ironic

Irony

Irony is a rhetorical device, literary technique, or situation in which there is a sharp incongruity or discordance that goes beyond the simple and evident intention of words or actions...

. However, it is a commonly used “professional slang” term in use among architects in the English-speaking world. A spear closet may actually have a door

Door

A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space....

 and be used as a storage closet. However, it may also simply be a “dead” space in a building which is completely surrounded by wall

Wall

A wall is a usually solid structure that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air...

s and which is inaccessible.