Words have meaning.
So does the phrase “arbitrary definitions”.
Arbitrary as in what's been in textbooks for maybe the last 30 years (at least what I know of)?
Arbitrary as in what everyone with any schooling in macro economics from pretty much any school understands that term to mean?
You know, my two year old speaks his own language too, no one can understand him, but it sound cute. Maybe you can come over and have a conversation with him?