Member of Parliament
A member of parliament (MP) is a member of the parliament of a country, who may have been elected in a democracy or otherwise selected in non-democracies.
In many countries with a bicameral system, this category includes specifically members of the lower house, as upper houses often have a different title. Member of Congress is an equivalent term in other jurisdictions.
Members of parliament seem to tend to form parliamentary groups (parliamentary parties) with members of the same political party.