What is "decocked"

Usage examples of "decocked".

She decocked the pistol and holstered it, buckling it in place, then ran to the edge of the roof, jumping down and landing in a roll.

McLanahan reloaded his weapon in the barrel, chambered a round, decocked the action, ejected the magazine, put the sixteenth round back in the magazine to fill it completely again, then holstered and secured the weapon.