Meaning of tarnation

tar•na•tion

Pronunciation: (tär-nā'shun), [key]
— Older Use. Older Use.
—interj.
  1. damnation.
—n.
  1. damnation; hell (used as a euphemism): Where in tarnation is that boy?
—adv.
  1. damned.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.