Definition of flashcube in US English:
 flashcube
nounˈflaSHˌkyo͞obˈflæʃˌkjub
historical A set of four flashbulbs arranged in a cube and operated in turn.
 Example sentencesExamples
-  Thousands of flashcubes popped for these and other daring routings.
 -  ‘The theft of a twelve-million dollar painting by Vermeer,’ said the officer sternly, and all three Californians blinked as a flashcube went off in their faces.
 -  It was a blur of revolving red lights on idling cars, and stern blue-uniformed men, and flashcubes popping everywhere.