There are many synonyms for the term "extension cord." Some of these synonyms include power cord, electrical cord, plug-in cord, and adapter for power. Another synonym could be a power strip, which is a device that has multiple outlets for plugging in electrical devices. Other synonyms could include power cable, extension lead, or electrical extension. The term power supply extension can also be used to describe this type of cord. Whether you prefer to call it an extension cord, a power cord, or something else entirely, these useful devices are a great tool to have around the house or office when you need to extend the reach of your power sources.