Shield, a tool of defense, can also be called a protection, guard, or barrier. The synonyms for shield also include coverage, shelter, safety, and screen. Shield can refer to a physical object such as a shield wall, a door, or a fence, but it can also indicate a protective barrier like a vaccine that shields the body from diseases. In addition to these synonyms, a shield is sometimes referred to as a bulwark, a rampart, or a fortification. Synonyms for the word shield are plenty and useful for conveying a sense of security and protection from harm.