attrib.
1
- denoting a switch or relay that makes and breaks contact rapidly, whatever the speed of the activating mechanism（开关, 继电器）突动的, 闪动的, 快动的。
2
- denoting a gun whose hinged barrel is secured by a spring catch（枪支）铰链枪管带弹簧销的。
noun
snap action
- the operation of such a switch, relay, or gun（开关、继电器或枪支的）快速操作。