A discharge tube is a device used to contain and manipulate electrical discharges through a gas or vacuum. It is often used in electronic devices, such as fluorescent bulbs or plasma screens. Synonyms for discharge tube include gas tube, vacuum tube, plasma tube, and discharge lamp. The term gas tube is used when the discharge occurs in a gas-filled tube, while vacuum tube refers to a discharge in a vacuum. Plasma tube is a synonym used when the discharge occurs in a high-temperature, ionized gas. And finally, discharge lamp is a term used when a gas discharge is used to produce light. All of these terms are used interchangeably depending on the specific context and application of the device.