Já

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

já Old Icelandic word can mean:

já

I)

já

adv. yea, yes; já, já! yes, yes!.

já

II)

já

(jái, jáða, jáðr), v. to say yes, assent to, with dat. (hann jáði því); já e-m e-u, to confess a thing to one; j. e-u upp, undan sér, to yield up.

Possible runic inscription in Younger Futhark:ᛁᛅ