Pear-shaped is a metaphor

Metaphor

A metaphor is a literary figure of speech that uses an image, story or tangible thing to represent a less tangible thing or some intangible quality or idea; e.g., "Her eyes were glistening jewels." Metaphor may also be used for any rhetorical figures of speech that achieve their effects via...

ical term with several meanings, all in reference to the shape of a pear

Pear

The pear is any of several tree species of genus Pyrus and also the name of the pomaceous fruit of these trees. Several species of pear are valued by humans for their edible fruit, but the fruit of other species is small, hard, and astringent....

, i.e. tapering towards the top and rounded at the bottom.

The comparison is less literal when the term is applied to people, where it means wide at the hips, a use that goes back to at least 1815, and one that can have either positive connotations (as in Venus figurines

Venus figurines

Venus figurines is an umbrella term for a number of prehistoric statuettes of women portrayed with similar physical attributes from the Upper Palaeolithic, mostly found in Europe, but with finds as far east as Irkutsk Oblast, Siberia, extending their distribution to much of Eurasia, from the...

) or negative, depending upon the context.

In the 20th century, another, more abstract use of the term evolved. When said of someone's voice, "pear-shaped" means rich and sonorous. The OED dates this use to 1925.

The third meaning is mostly limited to the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 and Australasia

Australasia

Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...

. It describes a situation that went awry, perhaps horribly wrong. A failed bank robbery

Bank robbery

Bank robbery is the crime of stealing from a bank during opening hours. According to the Federal Bureau of Investigation's Uniform Crime Reporting Program, robbery is "the taking or attempting to take anything of value from the care, custody, or control of a person or persons by force or threat of...

, for example, could be said to have "gone pear-shaped". Less well known in the US it generated some media interest when British politician Margaret Thatcher

Margaret Thatcher

Margaret Hilda Thatcher, Baroness Thatcher, was Prime Minister of the United Kingdom from 1979 to 1990...

 used the phrase in front of the world's press at one of her first meetings with U.S. President Ronald Reagan

Ronald Reagan

Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....

, with many reporters being unsure of the meaning of the term. The origin for this use of the term is in dispute. The OED cites its origin as within the Royal Air Force

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

; as of 2003 the earliest citation there is a quote in the 1983 book

1983 in literature

The year 1983 in literature involved some significant events and new books.-Events:*Ironweed by William Kennedy is published.*Salvage for the Saint by Peter Bloxsom and John Kruse is published. This is the final book in a series of novels, novellas and short stories featuring the Leslie Charteris...

 Air War South Atlantic. Others date it to the RAF in the 1940s, from pilots attempting to perform aerial manoeuvres such as loops. These are difficult to form perfectly, and are usually noticeably distorted—i.e., pear-shaped.

Other theories include:

• If the original plan was to be visualised as a perfect circle
  Circle
  A circle is a simple shape of Euclidean geometry consisting of those points in a plane that are a given distance from a given point, the centre. The distance between any of the points and the centre is called the radius....
  
  , then the failed execution might be pictured as a distorted figure, hence "pear-shaped".
• When a gun barrel fails, it exhibits a characteristic swelling at the point of failure, usually due to a bullet hitting an obstruction in the barrel or the barrel material failing due to excessive chamber pressure.
• In pottery, when a bowl, or whatever is being turned, ends up rather less circular than one would like.
• Round party balloons suggest celebration and success, but as they deflate they take on a pear shape.
• Some aircraft
  Aircraft
  An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
  
   engines become distorted (pear-shaped) in the event of failure.
• Early biplane
  Biplane
  A biplane is a fixed-wing aircraft with two superimposed main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...
  
   aircraft buckled into a pear-shape when they crashed, especially stalling on take-off.
• The phrase refers to the shape of a gas balloon
  Gas balloon
  A gas balloon is any balloon that stays aloft due to being filled with a gas less dense than air or lighter than air . A gas balloon may also be called a Charlière for its inventor, the Frenchman Jacques Charles. Today, familiar gas balloons include large blimps and small rubber party balloons...
  
   when it loses pressure. Gas balloons are spherical due to aerostatic pressure, but when they leak the gas rises to the top of the balloon and the neck bunches up, causing the balloon to look like an upside-down pear. The phrase hails from Victorian
  Victorian era
  The Victorian era of British history was the period of Queen Victoria's reign from 20 June 1837 until her death on 22 January 1901. It was a long period of peace, prosperity, refined sensibilities and national self-confidence...
  
   England
  England
  England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
  
   when gas balloons first became popular.
• In glass blowing it describes a failed circular blown vessel. If over heated the glass becomes too fluid and distorts under gravity as it cools, resulting in a pear-shaped vessel. This was particularly important with early experiments with cathode ray tubes, where creating a large spherical glass vessel was necessary. Blowing such an object was a challenge and often 'went pear shaped'.
• It may be a mechanical engineering
  Mechanical engineering
  Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the...
  
   term: White metal bearings (large stationary engines and the like) when worn become "pear shaped" sometimes, due to wear and tear. It was also used to indicate poor workmanship in the manufacturing.

External links

• OED's entry for the term, part of a Wordhunt
  Wordhunt
  Wordhunt was a national appeal run by the Oxford English Dictionary, looking for earlier evidence of the use of 50 words and phrases in the English language. New evidence found by members of the public in response to the appeal appears in the Oxford English Dictionary...
  
  appeal