A Gondorian coin mentioned in drafts of The Lord of the Rings appendixes (PM/45). It is likely related to mîr “precious thing”. Vyacheslav Stepanov suggested it might be an adjectival formation from an otherwise unattested verb *miria- “to esteem, value”, so meaning “a thing valued”.
Reference ✧ PM/45 ✧ ᴸN. mirian
Related
canath “quarter” is in Gondor used for a silver coin, the fourth part of the mirian ✧ PM/45