i-adjective
everlasting; eternal; unchanging
Literary adjective; usually used adverbially as 幾久しく to mean 'forever' or 'for a long time to come'. Often appears in formal or poetic contexts.
See also: 幾久しく
幾久しくお幸せに。
May you be happy forever.
この平和が幾久しく続くことを願う。
I hope this peace will continue eternally.