I think great dictionaries make a good or great starting point for defining contentious terms, but they are not the final authority. If nothing else their usage panels have experience with lexicographic word smithery, not an easy task as demonstrated in your college classes.
It’s helpful to define your terms, but it’s also unreasonable to ask people on the fly to construct a good definition. We have to make allowance for diplomacy and skill limitations. I see from the Amazon page for Kory Stamper’s book that it can take professionals 9 months to hammer out a suitable definition.
Some of these learned issues were discussed in the 2002 BBQ thread entitled, “Dictionaries do not win complex debates, you assholes.”