Rock barriers are structures made of rocks or boulders that are used to prevent soil erosion and provide protection against natural disasters such as landslides or flash floods. There are several synonyms for the term "rock barriers," including riprap, gabion walls, and revetments. Riprap refers to loose stones or boulders stacked together to form a barrier, while gabion walls are wire cages filled with rocks or other materials. Revetments are sloping structures made of various materials, including concrete, stone, or timber, designed to protect against shoreline erosion. These synonyms often have specific uses in different environments or for different applications, but all serve the same purpose of promoting safety and durability.