I use the terms liberal and conservative all the time. I've recently been wondering what that exactly means.
In general (according to me), conservative is the description of a viewpoint that was originally conceived at the onset of a group. Liberal is the description of a viewpoint that has changed since the onset of a group.
(In general, I usually talk as if I'm part of the "United States Citizens" group unless otherwise stated.)
Example 1: Group: United States Citizens. Original concept: role of federal government. Conservative: limited federal government. Liberal: more power to the federal government.
Example 2a: Group: Christian. Original concept: Abortion. Conservative: Abortion is always a sin. Liberal: Abortion is not a sin.
Example 2b: Group: Ancient Romans (~10 AD). Original concept: Abortion. Conservative: Abortion is morally permissible. Liberal: Abortion is never morally permissible.
Example 3: Group: Ancient Romans (~10 AD). Original concept: infanticide is morally permissible. Liberal: infanticide is never morally permissible.