switchblade
switchblade knife
flick-knife
flick knife

From the top drawer of the desk, she took her switchblade knife.

Into the left front pocket, she dropped her switchblade knife.

Now the switchblade knife was again in his other hand.

Something fell out of his pocket, the switchblade knife he'd threatened them with earlier tonight.

They found a switchblade knife under a table," she said.

Through the hole Henry has made with his switchblade knife.

The murder weapon was determined to be a switchblade knife.

He reached into his pocket, and pulled out a switchblade knife.

The other pulled a switchblade knife and pressed the point against his side.

He held the grenade in front of him as if it were a switchblade knife.