Dúnn

As defined by the Cleasby & Vigfusson Old Norse to English dictionary:

dúnn

(dýnn, Mart. 126), m. [Dutch dune; Engl. down; Swed. and Dan. dun; Germ. daun is prob. of Saxon or Dutch origin, as the d remains unchanged]:—down; taka dún ok dýna, n. G. l. i. 334; esp. used of bedclothes of down; the word occurs in the old heathen poem Gs., soft hann á dúni, 5; blautasti d., Mart. l. c.; á duni ok á guðvefi, Fms. x. 379; vöttu (pillows) duns fulla, a verse of Hornklofi. In Icel. ‘dún’ is chiefly used of eider-down, which word is undoubtedly of Icel. origin, Fr. édre-don, Germ. eder-don or eider-daun; the syllable er is the Icel. gen. æðar-dún, from nom. æðr (the name of the eider duck), acc. æði, gen. æðar. The eider-down, now so important as an article of trade, is never mentioned in old Icel. writers or laws; they only speak of the eggs (egg-ver). The English, during their trade with Icel. in the 15th century, seem first to have brought the name and article into foreign markets. At first it was bought in a rough state; Bogi Benediktsson in Feðga-æfi II records that a certain Jón í Brokey (born 1584), after having been in England, was the first who taught the Icel. to clean the down—var hann líka sá fyrsti hér vestra sem tók að hreinsa æðar-dún …, en áðr (i. e. during the English and Hanseatic trade in Icel.) seldist óhreinsaðr dún eptir Búa-lögum. Icel. say, hreinsa dún, hræla dún. The Danes say, have dun på hagen, to have down on the chin.

Possible runic inscription in Younger Futhark:ᛏᚢᚾᚾ
Younger Futhark runes were used from 8th to 12th centuries in Scandinavia and their overseas settlements