Mod – Dual usage – Can be used to describe modifications to a device or accessory (such as getting more vapor production out of your cartridges) or a design variation of a commonly manufactured electronic cigarette. In the latter context, mods typically use larger rechargeable Lithium Ion batteries and allow the user longer battery life and increased vapor production but at the cost of the device looking like a traditional cigarette. Many mods will also allow the user to increase or decrease the voltage of their device to achieve optimal performance.
Mod: Short for modification. This originally referred to modifying a flashlight or a battery to be used in vaping, but is now commonly used to refer to any vaping device that is not a cigalike.