Japla

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

japla

að, to mumble, as with a toothless mouth.

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