Fetta

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

fetta

tt, [fattr], to bend back; fetta fingr, to bend the fingers back; fetta fingr úti e-t, to criticise (unfairly); vide fingr.

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