Where does “Forth” come from?

Forth derives from Old English fēorþa, from Proto-Germanic fedurþô, from Proto-Indo-European kʷetwṓr, the word for the number four.

Forth (English): that flows for about 47 km (29 miles) from The Trossachs through Stirling to the Firth of Forth on the North Sea

Definitions

  1. that flows for about 47 km (29 miles) from The Trossachs through Stirling to the Firth of Forth on the North Sea

Ancestry of “Forth”, step by step

Forth traces back through two separate lines of ancestry.

via English Fourth

StepLanguageWordMeaning
1EnglishFourthThe Fourth of July
2Middle EnglishfourtheAlternative form of ferthe
3Middle Englishferthefourth; One of four equal parts of a whole; a...
4Old Englishfēorþafourth
5Proto-West Germanicfeurþōfourth
6Proto-Germanicfedurþôfourth

via Middle English forth

StepLanguageWordMeaning
1Middle Englishforth
2Old Englishforþ"expresses the continuation of an action"; out,...
3Proto-Germanicfurþąforward
4Proto-Indo-Europeanpr̥to-

Words derived from “Forth

Every word from Proto-Germanic fedurþô