Where does “donut spare” come from?

donut spare (English) comes from English donut, from English doughnut, from English dough, from Middle English dow, from Old English dāg, from Proto-Germanic daigaz, from Proto-Indo-European *dʰóyǵʰos, from Proto-Indo-European dʰeyǵʰ- — to knead; to form, to shape.

donut spare (English): A type of spare tire. The undersized spare wheel (tire and rim) provided by automotive manufacturers in lieu of a full-sized tire, for use in emergencies, when one of the regular ones can no longer be used

Definitions

  1. A type of spare tire. The undersized spare wheel (tire and rim) provided by automotive manufacturers in lieu of a full-sized tire, for use in emergencies, when one of the regular ones can no longer be used

Ancestry of “donut spare”, step by step

donut spare traces back through two separate lines of ancestry.

via English donut

StepLanguageWordMeaning
1EnglishdonutA deep-fried piece of dough or batter, commonly...
2EnglishdoughnutA deep-fried piece of dough or batter, commonly...
3EnglishdoughA thick, malleable substance made by mixing flour...
4Middle EnglishdowAlternative form of dogh
5Old Englishdāgdough
6Proto-Germanicdaigazsoft; that which is formed or kneaded; dough
7Proto-Indo-European*dʰóyǵʰossomething that is kneaded, formed
8Proto-Indo-Europeandʰeyǵʰ-to knead; to form, to shape

via English spare

StepLanguageWordMeaning
1EnglishspareScant; not abundant or plentiful; Sparing;...
2Middle Englishspare
3Old Englishspærscanty
4Proto-Germanicsparazsparing, frugal
5Proto-Indo-Europeansper-to fidget, twitch; to push; to be quick; to...
Every word from Proto-Indo-European dʰeyǵʰ-