Some time ago, I finally figured out the conservative definition of "liberty." For years I had no idea what they meant by it, because they usually used it in the same breath as they advocated denying someone life or a reasonable expectation of participation in society. Then one night, during a long, long discussion with a right-libertarian, I finally understood. While I define liberty as the right to life and societal participation, when we strip things down to the bones, conservative thought defines liberty as the right to control and retain ownership of property.
It is when these two definitions of liberty come into conflict that we get the biggest liberal vs conservative clashes. Slavery is the most irreducible example of this - conservatives were fighting to not be deprived of their property, while liberals were arguing that the right of the human being to live and participate in society overruled the property thing. Jim Crow is only one step removed from that - conservatives argue that the right of property owners to do whatever they want with their property trumps the right of other people to live and participate in society. Modern conservatives argue that the wealthy should have the right to prevent the poor from having access to voting, and call that liberty... because their definition of liberty prioritizes property rights over human rights.
This has helped me understand a lot of things I previously thought were just insane or stupid. The most conservative conservatives believe that the oligarchy their policies seek to bring about is the apotheosis of liberty... a world where the property owners have absolute control, and almost all of the country is private property. To them, that isn't a bug, it's a feature. A property owner having tyranny over anyone who lives or works on the property he owns is "liberty." If one of his "subjects" doesn't like it, they have the right to go find another property owner to control them, or they can attempt to buy their own property... if they were lucky enough to have a previous property owner who payed them well enough to allow them to do so, of course.
An interesting observation on a Making Light open thread by Leah Miller. It's comment 617, and has subsequently spawned a big sub-thread I've barely touched. But I wanted to share.