A ford in the river Sirion (S/131), a combination of brith “gravel” and iach “ford” (SA/brith, UT/54), hence: “✱Gravel Ford”.
Sindarin
Brithiach
noun. gravel ford
brithiach
place name. *Gravel Ford
Elements
Word Gloss brith “gravel” iach “ford”
brith (Ilk. “broken stones, gravel”) + #iach (“ford”)