"Wraith" was in the supernatural lexicon before Stargate and even before Tolkien, I'll bet.
You'd be a winner.
Wraith [also, wrath, wrayth, wraithe, wreath], etym.
chiefly Scottish, of obscure origin.
an apparition or spectre of a dead person; a phantom or ghost; attes. 1513, Douglas AEneid
xi.93 - In diuers placis The wraithis walkis of goistis that are deyd; a
1585, Polwart Flyting w. Mongomerie
638 - Thy speach ... is espyed, That wrytes of witches, warlocks, wraiths, and wratches; b.
an immaterial or spectral appearance of a living being, freq. regarded as portending that person's death; a fetch; attes: 1513, Douglas AEneid
x.xi.127 - Thydder went this wraith or schaddo of Ene; 1597, Jas. VI, Demonol.
These kindes of spirites, when they appeare in the shaddow of a person ... to die, to his friends ... are called Wraithes in our language.