Дума - /'du-ma/- Duma

The word "Duma" originates from the Russian verb"dumat" which means "to think", "to consider" which explains the nomination of state structure with such a word.

The State Duma in the Russian Empire and in the Russian Federation represents the lower chamber of the parliament. This term also refers to the council of early Russian rulers known as the Boyar Duma. It was an advisory council to the grand princes and tsars of Russia. During the reign of Peter the Great it was abolished and its functions were transferred  to the Governing Senate. In Imperial Russia Municipal dumas existed. Nowadays it can also denote city and regional legislative bodies in the Russian Federation. 

You see the State Duma of Russian Federation during one of your Moscow tours.