Halidom \Hal"i*dom\ (h[a^]l"[i^]*d[u^]m), n. [AS. h[=a]ligd[=o]m holiness, sacrament, sanctuary, relics; h[=a]lig holy + -d[=o]m, E. -dom. See Holy.]

1. Holiness; sanctity; sacred oath; sacred things; sanctuary; -- used chiefly in oaths. [Archaic] [1913 Webster]

So God me help and halidom. --Piers Plowman. [1913 Webster]

By my halidom, I was fast asleep. --Shak. [1913 Webster]

2. Holy doom; the Last Day. [R.]

--Shipley. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Halidom \Hal"i*dom\, n. [AS. h[=a]ligd?m holiness, sacrament, sanctuary, relics; h[=a]lig holy + -d?m, E. -dom. See Holy.]

1. Holiness; sanctity; sacred oath; sacred things; sanctuary; -- used chiefly in oaths. [Archaic]

So God me help and halidom. --Piers Plowman.

By my halidom, I was fast asleep. --Shak.

2. Holy doom; the Last Day. [R.]

--Shipley.

Source: Webster's Revised Unabridged Dictionary (1913)