In Finnish the name of the parliament is Eduskunta, edus from edustaa, to represent and kunta, a multi-purpose word for a body of people. A member of parliament, then, is kansanedustaja, from kansa, the people, and edustaja, yes, you guessed it, a representative. Thus, we have simply "A Representative Body" or "A Body of Representatives", formed of "Representatives of People".
It is very simple and self-explanatory, but it does definitely lack the aura of authority and age-old power carried by some of the foreign and, frankly, a bit archaic terms. Seeing the Finnish parliament discussed in in the other official language as riksdag makes it, to me, to seem more special...