safety lock

a lock designed to prevent picking.

Origin of safety lock

First recorded in 1875–80

The bore is made of any rifle calibre for any small-arm ammunition, and is fitted with a safety-lock.

The Romance of Modern Invention |Archibald Williams
It had to be slid sideways for a quarter of an inch, a safety-lock feature.

The Blue Ghost Mystery |Harold Leland Goodwin
When the firing is stopped be sure to turn on the safety-lock.

Manual of Military Training |James A. Moss
Some one, a woman I believe, has correctly defined it as "the safety-lock upon the property of the people."

Sophisms of the Protectionists |Frederic Bastiat

To bribe the guard was foolhardy because the guard did not know the combination of the safety-lock.

The Unpublishable Memoirs |A. S. W. Rosenbach