Síðastr

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

síðastr

a. latest, last (sá skal fyrstr út ganga er s. gengr inn); it síðarsta, at the latest (þá skal stefnt it síðarsta viku fyrir þing).

Possible runic inscription in Younger Futhark:ᛋᛁᚦᛅᛋᛏᚱ

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