means A holster is a fitted case, usually of leather or molded synthetic, designed to hold a firearm (or sometimes a tool) securely on the body for quick access.

from From Dutch 'holster,' a covering or case for a pistol, which English borrowed in the 1660s. It belongs to a wider Germanic family of words for a sheath or hiding-place — likely related to the same root that gives us 'holdster'-type ideas of concealment and the old notion of something enclosed. The deeper ancestry is a cousin to words meaning 'to cover' or 'to hide,' fitting for a thing whose purpose is to keep a weapon tucked away until the moment it isn't.