I agree, but cathedrals seem to be more specific to some cultures and not others. Maybe. Not really an expert on the relation of temples and religion. I tend to think of temples and cathedrals being associated to cities because the only time we hear about religious structures and their function in society is when they are grand and enduring structures.Both the statements "Town means walled villiage" and "Town means a settlement of a certain size, depending on juristiction" are true, and rely on different modern English meanings of "mean". But disagreeing with one and saying "actually" the other is simply wrong; the use you disagreed with is perfectly colloquial English.
Your error was not understanding modern English. Words, including "mean", mean more than one thing.
Anyhow, using Town vs Villiage for walled and unwalled in D&D would make a lot of sense.
In my headcannon, "suoerstitious" rites are performed - hedge magic - to secure dwellings and settlements and roads against monsters. Individual homes would be warded thus way.
Villiages would be clumps of such individual homes. Then a low grade stone wall with rudimentary warding would be added; as it progresses, the villiage would be upgraded to town.
Using catheral city for the definition of City also works along these lines; a cathedral would be a ritual anchor for the wards of a settlement. Its spire a magical antenna for ley lines, the services prayer wheels fueling the wards.
How true has that held for polytheistic cultures that tends to dominate D&D's worlds is a different question, one I am by no means an expert on. When I've tried to find out more, it's always back to a handful of religions like ancient Greek because for the most part they built temples to specific gods and the gods lived there. That, and the temples are cool looking. Other than that, I plead ignorance, but it's also a topic for another thread.
The real question is, what is a hamlet? A group of buildings where they let ham ... umm ... pigs roam free? Inquiring minds want to know!