Horse-brier is a term commonly used to describe a thorny vine or shrub that is known for its prickly stems and leaves. However, there are several other synonyms for the term horse-brier that can be used depending on the region or context. Some of the most common synonyms include greenbrier, catbrier, prickly-ivy, and bullbrier. These terms refer to different species of plants that share similar characteristics to the horse-brier, including thorns, prickly leaves, and woody stems. Regardless of the name used, these plants can be quite challenging to manage or remove due to their tough nature, but are often used in decorative or medicinal purposes.