adjective
favorable to progress or reform, as in political or religious affairs.
(often initial capital letter) noting or pertaining to a political party advocating measures of progressive political reform.
of, pertaining to, based on, or advocating liberalism, especially the freedom of the individual and governmental guarantees of individual rights and liberties.
favorable to or in accord with concepts of maximum individual freedom possible, especially as guaranteed by law and secured by governmental protection of civil liberties.
The Founding Fathers were liberals. Modern leftists are anything but that.