折刀

[ noun ]
a large knife with one or more folding blades
<noun.artifact>

Clasp \Clasp\, n.
1. An adjustable catch, bent plate, or hook, for holding
together two objects or the parts of anything, as the ends
of a belt, the covers of a book, etc.

2. A close embrace; a throwing of the arms around; a
grasping, as with the hand.

{Clasp knife}, a large knife, the blade of which folds or
shuts into the handle.

{Clasp lock}, a lock which closes or secures itself by means
of a spring.