The term "electric chairs" is generally associated with execution by electrocution. However, there are other synonyms that can be used to refer to this type of capital punishment. One of the most common synonyms is "electric chair apparatus," which is a more formal way to refer to the machine used to administer the electric shock. Another synonym is "death chair," which has a more ominous connotation. "Electric throne" or "electric seat" are other options that may be used to refer to the device used for electrocution. While these synonyms may be less commonly used than "electric chair," they can add variety and interest to your writing.