"orthodox" Theravada

excerpt from merriam webster dict.

orthodox
/ˈôrTHəˌdäks/
The term orthodox generally refers to beliefs, behaviors, or traditions that are widely accepted, conventional, or aligned with established standards. Literally translated from Greek, it means "right belief" or "correct teaching". [1, 2, 3, 4]

Etymology and Literal Meaning
The word comes from the Greek words orthos (meaning "right," "straight," or "true") and doxa (meaning "opinion," "belief," or "glory"). Therefore, the literal meaning is "right opinion" or "true doctrine". [1, 2]

What is "orthodox" Theravada?

Whenever you hear someone claim they're orthodox,

you should be asking, "Orthodox with respect to what or who?"

Is it orthodox with respect to the Buddha's spoken words during his lifetime?

Is it orthodox with respect to the Buddha's recorded words within the first few hundred years?

Or is it orthodox with respect to a corrupted Buddhism 500 years after the Buddha?

Related

You can hear sounds in the four jhanas, AN 10.72, and is 'Theravada' an oxymoron?