To hear the common usage of this word (in the phrase 'shut your pie hole
') you'd have to imagine it must have come to mean 'mouth
' simply because that is the 'hole' (e.g. bodily orifice) which one would use to consume pie
. But in actuality, the word 'pie-hole' derives from an Eighteenth Century Scottish
term for the holes through which laces
were drawn in boot
s -- which openings were initially simply called eyelet
s or 'eye-holes,' owing to their similarity to the eye of a needle. And which phrase probably got changed over from eye-hole to pie-hole simply owing to a rhythmic similarity of sound. The 'p' it is noted, might have come from pig
, which resembled the Danish word for a prick
(meaning a small hole, bootlace holes being made by using a leather punch to 'prick' the boot). And so by the mid Nineteenth Century
the word 'pie hole,' because it represented this little tiny hole for shoe-lacing, came to be used euphemistically among the Scottish to reference any really small hole, especially anything which would be a tight fit for a person to squeeze through for example (as in, the boy could barely squeeze through that pie-hole in the fence). Now, when and how it came to refer to the mouth (and especially to the mouth which somebody was commanding to be shut), well that remains a mystery
. But you can bet it began with the Scottish.
One additional note on usage: it appears that when instructing somebody to shut their pie hole, it is most amusing to pronounce/spell the possessive pronoun as "yer" -- as in, "shut yer pie hole, ye scalliwag!!"
An etymological dictionary of the Scottish language: illustrating the words in their different significations
. Volume 2. By John Jamieson, Edinburgh, 1808.