In Netherland it traditionally means the place has city rights. But Den Haag (The Hague) never had city rights (being the seat of the count of Holland), so despite being 500k large, it's technically not a city. Though in all other aspects it really is. A much younger city, Almere (200k+), a fairly new suburb of Amsterdam but now the 5th largest city in the country, is far too young for such city rights. But we also have "cities" that have only a few hundred inhabitants.

The province of Friesland famously has 11 cities, but many of those are tiny, and it doesn't include several of the largest towns that are not technically cities.