Webster's definition refers only to the later, (over)specific sense of this word as used in
law. When
Kantian philosopher
Wilhelm Windelband coined it in the late 1800s, he had a much cooler, more useful sense in mind, as
WordNet's definition illustrates:
Nom`o*thet"ic
adj : (psychology) relating to or involving the search for abstract universal principles.
Windelband built the word from the Greek nomos, for law, and thetes, one who establishes. He used the term to distinguish idiographic approaches to history (and by inference, knowledge in general), in which the historian seeks to understand events as things in and of themselves, from a nomothetic approach, in which the historian looks at how particular events illustrate broad patterns, laws, or cycles.
So now all you seekers of broad truth, Alexandrian pattern-writers, and Noders-for-the-Ages know what to call yourselves, your approach, and your nodes.