Eigintunga

As defined by A Concise Dictionary of Old Icelandic (Geir Zoëga):

eigintunga

f. one’s own native tongue.

Possible runic inscription in Younger Futhark:ᛁᛁᚴᛁᚾᛏᚢᚾᚴᛅ

Also available in related dictionaries:

This headword also appears in dictionaries of other languages closely related to Old Icelandic.

• Old Norse - Cleasby & Vigfusson Dictionary