Here are some possibilities:
1. Misspelling:
* Sub-source: This could be a hyphenated word referring to a smaller or less important source of information or material.
* Source: Perhaps the original word was simply "source" and the "sub" was a typo.
2. Specialized term:
* Subsource could be a technical term used in a specific field, such as software development, finance, or law. Without context, it's impossible to say for sure.
To understand the meaning of "subsource," you need more context. Please provide the sentence or situation where you encountered this word.