One possible meaning of the term is a mindset that the traditional way of doing or seeing things is universally correct for both the past and the future.
An entirely other defenition is that of the Tory philosophy: the traditional way of doing things might not necessarily be the best possible but it's better to keep using what works than blindly following people who speak from ideological conviction. Change should be allowed but incrementally as a continous proces of evolution, rather than going from conservativism to revolution, then being conservative of the fruits of the revolution till a new revolution comes, and so on (the French way of doing things)
There are different definitions in different countries, but the above two seem to be the most widely used. Of course even within a country people can have different ideas of what it really is.
In the Neth's people mostly think of the former definition and it's usually taken as a slur from left to right. The Socialist Party for example is closer to "old school" socialism than the Labour party is (wich is arguably similar to its modern British counterpart) and has occasionally been called conservative for it.
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