Rubblestone is a type of masonry made using rough, irregularly shaped stones. However, there are many synonyms for rubblestone that can be used to describe this type of construction material. Some of these synonyms include cobblestone, fieldstone, and flagstone. Cobblestone is typically a smaller, rounded stone used for paving, while fieldstone refers to larger, more irregular stones used for building. Flagstone, on the other hand, is a thin, flat stone used for paving or building walls. Other synonyms for rubblestone include boulderstone, rockface, and natural stone. These terms can be used interchangeably depending on the context and type of stone being used.