A vast number of explanations for this phrase has been suggested; many of these are no longer viable in light of what is now known about the phrase's history. It is further complicated by the fact that earlier versions of the phrase referred to 'the whole six yards'.

The most commonly offered explanation is that World War II (aircraft machine gun belts were nine yards long. There are many versions of this explanation with variations regarding type of plane, nationality of gunner and geographic area. This theory is no longer considered viable, since the phrase predates World War II.

Another common explanation is that it is a cubic measure and refers to the volume of a concrete mixer. This theory, too, is inconsistent with the phrase's history that precedes mechanical concrete mixers.

Many of the popular candidates relate to the length of pieces such as Scottish kilts. No single source verifies that any one of those suggestions was the actual origin.

Jesse Sheidlower, editor-at-large for the Oxford English Dictionary, has argued that the phrase does not have a concrete meaning, comparing it to 'the whole shebang'.

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