Given the file path:
/some/path/abc.txt
The filename is "abc.txt", and extension is "txt".
What is the "industry standard", unambiguous name for the "abc" part?
For reference, in both java's older java.io and newer java.nio libraries, filename means "abc.txt", and there is no term (ie the library APIs don't support) for the "abc" part.
I believe that's just called the "filename" as well, which makes thing fairly confusing:
Discussions of filenames are complicated by a lack of standardisation of the term. Sometimes "filename" is used to mean the entire name, such as the Windows name c:\directory\myfile.txt. Sometimes, it will be used to refer to the components, so the filename in this case would be myfile.txt. Sometimes, it is a reference that excludes an extension, so the filename would be just myfile. Such ambiguity is widespread and this article does not attempt to define any one meaning, and indeed may be using any of these meanings. Some systems will adopt their own standardised nomenclature like "path name", but these too are not standardised across systems.
If it's important, you'll have to make sure you clarify exactly what "filename" you're talking about.
filenames.with.several.periodsand.dotfiles. But I doubt you´ll even find a standard one for Windows only (the main platform that cares about extensions).