IPA: //ˈflæʃ.kjuːb//
KK: /ˈflæʃˌkjub/
A small cube that has four flashbulbs and turns to use a new bulb each time a photo is taken with a camera.
The photographer used a flashcube to ensure the pictures were bright and clear.
Flashcube → The word is a compound of "flash" (from Old English *flaescian*, meaning to shine or emit light) and "cube" (from Latin *cubus*, meaning a three-dimensional geometric shape with equal sides). The term "flashcube" refers to a device that emits a bright flash of light, typically used in photography, shaped like a cube.
Think of something that 'shines' ('flash') and is 'cube-shaped' ('cube') — that's how a flashcube emits a bright light in a compact form.
No commonly confused words.