The phrase "blank space" can be replaced with a variety of synonyms, each providing a slightly different nuance. "Empty spot" conjures up an image of a gap in an otherwise filled area, while "vacant area" suggests a space that has been intentionally left empty. "Clear zone" implies a space that is actively maintained, while "void" draws attention to the absence of anything in the space. "Unoccupied territory" suggests an area waiting to be claimed, while "blank canvas" evokes a sense of potential creativity. Ultimately, the synonym chosen will depend on the specific context and desired tone of the communication.