I did not give an extensive definition because the self-description of liberalism, by liberals, is at odds with the historical actions of liberalism. It could be distracting and take a while to get the point across.

For example, liberalism self-defined with maximizing individual liberty while it also advocated for the “freedom” of corporations to work you as many hours as it could while shitting down your unionizing effort with violence. Liberalism also self-defined as favoring democracy and everyone having a say, but implemented this in a racist and sexist way that placed capital in charge while also colonizing others and depriving them of self-determination.

The common thread is really just that it is the dominant ideology of capitalism, its function is to extoll the virtues of capitalism and tying it to an illusion of liberation and self-determination while actually working against both of those things, as under capitalism, capital works against both struggles. The person that liberals have you read as foundational to liberalism, John Locke, worked to support an American settler colony and its slavery rules and explicitly supported child labor. Then, as today, there is a difference between how political figures present themselves and what their advocacy actually entails.