Halidom
Halidom (hal"i*dum) , noun
[Anglo-Saxon hāligdōm holiness, sacrament, sanctuary, relics; hālig holy + -dōm, English -dom. See Holy.]
1.
Holiness; sanctity; sacred oath; sacred things; sanctuary; -- used chiefly in oaths. [Archaic]
So God me help and halidom.
By my halidom, I was fast asleep.
2.
Holy doom; the Last Day. [Rare] — Shipley