Gadzooks!

In my unending quest to understand odd words I looked this one up on the OED.com and found no hits! Could it be? A word missing from the OED? Well this is what Answer.com told me:

gad·zooks (găd'zūks') pronunciation
interj.

Used as a mild or ironic oath: “Gadzooks! Is there a panic detector, akin to a smoke detector, that sniffs anxiety in the air?” (George F. Will).

[Perhaps alteration of God's hooks, the nails of the crucifixion of Christ.]