Þrínættr

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

þrínættr

a. three nights old.

Possible runic inscription in Younger Futhark:ᚦᚱᛁᚾᛅᛏᛏᚱ

Also available in related dictionaries:

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

• Old Norwegian - Johan Fritzner's Dictionary