Definition: The term "4.1_64" refers to an error in a certain version of a software application that occurred during its initial development and was later fixed. The "error code" 4.1 indicates it was found in the software, while 64 is a numerical value indicating how many bits of memory were allocated for this particular error (usually 8 for a common programming language). This could be an intentional mistake, a bug, or an error related to some specific aspect of the application's functionality or design. It's important to note that the correct term and definition might vary based on context and the specific software application at hand.