Webster (online) gives for "liberal"

1. Showing or characterized by broad-mindedness; "a broad political stance"; "generous and broad sympathies"; "a liberal newspaper"; "tolerant of his opponent's opinions".

2. Having political or social views favoring reform and progress.

3. Tolerant of change; not bound by authoritarianism, orthodoxy, or tradition.

4. Given or giving freely; "was a big tipper"; "the bounteous goodness of God"; "bountiful compliments"; "a freehanded host"; "a handsome allowance"; "Saturday's child is loving and giving"; "a liberal backer of the arts"; "a munificent gift"; "her fond and openhanded grandfather".

5. Not literal; "a loose interpretation of what she had been told"; "a free translation of the poem".

Noun
1. A person who favors a political philosophy of progress and reform and the protection of civil liberties.

2. A person who favors an economic theory of laissez-faire and self-regulating markets.





IMHO use 2 would not be common in England other than in a very specialised constitutional analysis referring to specific constitutional authors' theories.