means the trait of refusing to change one's mind, position, or course of action even in the face of good reasons, pressure, or evidence.

from From "stubborn," which surfaces in Middle English as "stiborn" or "stuborn," of obscure origin — its root is genuinely unknown. The popular guess links it to "stub," the unbudging stump left after a tree is felled, which fits the meaning so neatly it's hard to resist; but scholars don't actually confirm that connection. The "-ness" is the plain old English suffix that turns a quality into a thing you can name and accuse someone of.