The literal meaning (i.e. "Block Cracker") refers to the aerial bombs of the same name used in the Second World War (aware of this fact, I think that this term should be used rather restrictively). In a figurative sense, this means "scoop" or "street sweeper" and is used especially in the media industry for particularly successful cinema films. However, this "modern" term is increasingly being used for successful products in general, for example also for particularly effective medicines (!) or outstanding wines. For more information about this Thama see also under Wine of the century and most expensive wines in the world.