Ei

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

ei Old Norse word can mean:

ei

and ey (cp. also æ), adv. [cp. Gr. αἰών; Lat. aevum; Goth. aivs = eternity, everlasting time: hence are derived the O. H. G. eva, A. S. æ, Hel. êo, in the metaph. sense of law (the law being symbolical of what is everlasting), which word still remains in the mod. Germ. ehe = marriage; whence the mod. Germ. echt = genuine, mod. Dan. ægte, mod. Icel. ekta, q. v. (Grimm)]:—ever; the phrase, ei ok ei, or ey ok ey, for ever and ever; gott ey gömlum mönnum, gott ey ungum mönnum, Landn. 45; öllungis muntu hafa þau ei ok ei, Hom. 15, Al. 120; hans ríki stendr ei ok ei, 160; Guðs ei lifanda, BlaS. 43: the proverbs, ey sér til gyldis gjöf, Hm. 146; ey getr kvikr kú, 69; ey lýsir mön af mari, Vþm. 12; ey bað hon halda, Hkv. 1. 4; ey var mér týja, Akv. 27; lifa ey, Hm. 15, 34; er ok ey eða ei þat er aldregi þrýtr, Skálda 172; ei at vera, 677. 3; til hins sama var ey at ætla, BS. i. 108.

ei

II. [Dan. ei, Swed. ej], not ever, not, properly a contraction from ei-gi, in the MSS. freq. spelt é or e̅g̅; ei is often used in mod. writers, but not in speech; it is also used now and then in Edd. of old writers, though it is doubtful whether it is there genuine.

ei

2. ey in a negative sense; ey manni, no man, Vþm. 55; vide eyvit.

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