Ar stêr Forth zo ur stêr eus reter Bro-Skos hag a aber er Firth of Forth.

An anv

Bodotria e vefe an anv kozh, hervez :

• Tacitus, Agricola, 23,1; 25,1; 25,3 : BODOTRIA
• Ptol. II,3,4 : BODERIA AESTUARIUM
• Ravenna 108₃₂ : BDORA

Dielfennadur, hervez Rivet & Smith, p. 269-271 : "It seems that Forth may well derive from *Voritia (*vo- 'somewhat' plus a root as in Irish rith 'act of running', that is 'slow running one', this *Voritia being later name or by-name ...", da lavaret eo ur stêr difonn he red.

Hervez A.D Mills : "The Celtic river name probably means 'the slow flowing one", "an hini a red difonn".

Levroniezh

• A.L.F. Rivet & Colin Smith : The Place-Names of Roman Britain. B.T. Batsford Ltd. London. 1979 - 1982
• A.D. Mills : Oxford Dictionary of British Place Names. Oxford University Press. 1991 ... 2003