Earlier quoted context omitted.
Then why not just say 'domain-specific meaning?' Term of art doesn't really have a clear meaning in general (native English speaker, and this is the first time I've heard this), and it's unclear/ambiguous as to what it actually indicates.
"Jargon" is a good word for this case.
"Term of art" only implies that it is the specific phrasing used by practitioners to describe the matter at hand.