Where does “seat-mile” come from?

seat-mile (English) comes from English mile, from Middle English myle, from Old English mīl, from Latin mīlia, from Proto-West Germanic mīliju, from Latin Mīlle, from Proto-Italic smīɣeslī, from Proto-Indo-European smih₂ǵʰéslih₂.

seat-mile (English): A unit of measure of passenger carrying capacity,...

Definitions

  1. A unit of measure of passenger carrying capacity,...

Ancestry of “seat-mile”, step by step

seat-mile traces back through two separate lines of ancestry.

via English mile

StepLanguageWordMeaning
1EnglishmileThe international mile: a unit of length...
2Middle Englishmylemile; The time it takes to walk a mile;...
3Old Englishmīlmillet; mile
4Latinmīlia
5Proto-West Germanicmīlijumile
6LatinMīllethousand; 1000
7Proto-Italicsmīɣeslīthousand
8Proto-Indo-Europeansmih₂ǵʰéslih₂

via English seat

StepLanguageWordMeaning
1EnglishseatSomething to be sat upon; A location or site; The...
2Middle Englishsete
3Old Englishsǣtehouse
4Proto-Germanicsētijąseat
5Proto-Indo-Europeansḗd-to sit
Every word from Proto-Indo-European smih₂ǵʰéslih₂Every word from Proto-Italic smīɣeslīEvery word from Latin Mīlle