Definition of "zam"

Then suddenly — Zam! Zowie! Smash! The Post sends back an article which I was positive it would buy, and which, in fact, it had ordered. One manuscript after another is flung back into my face […]

1945, The Author and Journalist, volumes 30-31, page 9

You never know when some enemy of the Free World might worm his or her way into your confidence and then — ZAM! Wipe you out.

2007, J. W. Brodie-Innes, The Devil's Mistress, page 21