Gizka

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

gizka

að, to guess; g. á e-ð, to guess at a thing; á-gizkan, a guess.

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