In firearms terminology, which term is associated with the firing mechanism that requires the user to manually prepare the hammer?

The term associated with the firing mechanism that requires the user to manually prepare the hammer is referred to as "single action." In a single action firearm, the hammer must be cocked manually before each shot, either by pulling the hammer back or by the action of cycling the firearm. This mechanism only performs one action with each pull of the trigger, which is to release the hammer, striking the firing pin.

In contrast, a double action mechanism is designed to both cock and release the hammer with a single pull of the trigger, allowing for faster follow-up shots but reducing the user's control over the trigger pull. The term "manual safety" refers to a safety feature that prevents the firearm from being discharged until the safety is disengaged and isn't directly related to the firing mechanism itself. The term "cocking mechanism" is a broader term that can apply to both single action and double action firearms, encompassing various methods of preparing the hammer for firing. Thus, "single action" accurately describes the specific requirement of manually preparing the hammer before firing.