Actually, the original word has nothing to do with continuity. That's a later adoption of it from Latin to English. So to be precise, you don't need continuity. It's just a re-adoption of the same word form the original Latin.

But many without autism don't have that need for precision so they get confused by mixing up later word use in different contexts like you did there.

The present day meaning describes a continuum. The term could indeed be defined in the anachronistic terms you describe so it is anachronistic, which is a reasonable complaint when something enters common usage. We see terms redefined all the time thusly

UPDATE I have exceeded my grace with HN spam controls

The confusion arises from the direct import of a medical Latin term which means what it means in Latin, into the modern colloquial- this is important information