The Geiger-Muller counter is an essential tool for measuring levels of radiation in various settings. However, there are several synonyms for this important device, including the Geiger Counter, GM counter, radiation detector, radiation monitor, and radiation survey meter. Each term is commonly used interchangeably with the Geiger-Muller Counter and refers to the same type of instrument. Each term is used to describe the device's purpose and capability, which is to detect and measure ionizing radiation. No matter what synonym is used, the Geiger-Muller Counter remains an indispensable device for individuals working with or around sources of radiation.