Terminology defines “node” as “Any DOM object.” It depends on the meaning of “DOM object” which Terminology does not define, despite defining “DOM”.

The definition as-is would seem to include things like DOMException and Range, which is unintuitive.

I think the closest thing to “node” in the DOM Core spec is “an object which participates in a tree” <http://www.w3.org/TR/domcore/#concept-tree-participate> or borrowing from the structure of the definition of Element, a node could be an object which implements the Node interface.