The word "yard-arm" is typically used to refer to one of the horizontal beams on a ship's mast that hold up the sails. However, there are several synonyms for this term that can be used interchangeably in different contexts. Some of the most common synonyms for yard-arm include spar, boom, gaff, and yard. These terms are often used by sailors and shipwrights to describe various parts of a ship's rigging, and can be helpful in communicating about specific components of a vessel. Whether you're a boating enthusiast or just interested in maritime history, understanding these synonyms can deepen your knowledge of seafaring and sailing technology.