IPA: //ˈflæʃɡʌn//
KK: /flæʃɡʌn/
A device used in photography that produces a bright light to help illuminate a scene when taking pictures.
The photographer used a flashgun to capture the perfect shot in low light conditions.
Flashgun → The word is formed from "flash" (from Middle English *flaschen*, meaning to emit light suddenly) and "gun" (from Old English *gunne*, meaning a device for shooting). A flashgun is a device that emits a sudden burst of light, typically used in photography.
Think of a device that 'emits light suddenly' ('flash') and is a 'shooting device' ('gun') — that's how a flashgun works.
No commonly confused words.