A fuller name of Fornost translated “Norbury of the Kings” (LotR/993), a combination of the city name with erain, plural of aran “king”.
Sindarin
Fornost Erain
noun. North(ern) fortress of the kings
fornost erain
masculine name. Norbury of the Kings
Elements
Word Gloss Fornost “Norbury, (lit.) Northern Fortress” aran “king, lord, chief, (lit.) high or noble person, king, lord, chief, (lit.) high or noble person; [N.] lord (of a specific region)”
Fornost Erain
Fornost Erain
Fornost Erain is Sindarin. It means "Northern Fortress (of the) Kings"; from forn "north" and ost "fortress", and erain is the plural of aran. The Fornost component is a direct cognate to Quenya Formenos. It was translated as "Norbury of the Kings" (from supposedly Old English norð-burg), which represents its Westron name.
forn (“right, north”) + ost (“fortress, stronghold”), erain (pl. of aran “king”)