unreturning

From un- +‎ returning.

unreturning (not comparable)

1. Not returning; not coming back.
   • 1842, Lydia Sigourney, Poems, Tomb of a Young Friend at Mount Auburn, page 34:

     So, thou hast pass'd the unreturning gate,
     Where dust with dust doth linger, and gone down
     In all the beauty of thy blooming years
     To this most sacred city of the dead.

   • 1908, Edmund Doidge Anderson Morshead, Four Plays of Aeschylus, Dedication, page 4:

     For gifts that die have living memories—
     Voices of unreturning days, that breathe
     The spirit of a day that never dies.

• unreturningly

• return