Where does “firth” come from?

firth (Scots) comes from Middle English fyrth, from Old Norse fjǫrðr, from Proto-Norse ᚠᛖᚱᚦᚢᛉ, from Proto-Germanic ferþuz, from Proto-Indo-European pértus, from Proto-Indo-European per-, from Proto-Indo-European pr̥tós — passed , crossed.

Ancestry of “firth”, step by step

StepLanguageWordMeaning
1Middle Englishfyrth—
2Old Norsefjǫrðrfirth, fjord
3Proto-Norseᚠᛖᚱᚦᚢᛉ—
4Proto-Germanicferþuzinlet, fjord
5Proto-Indo-Europeanpértuscrossing
6Proto-Indo-Europeanper-before, in front; first; to go through
7Proto-Indo-Europeanpr̥tóspassed , crossed

Words derived from “firth”

Every word from Proto-Indo-European pr̥tós →Every word from Proto-Indo-European per- →Every word from Proto-Indo-European pértus →