2. Constituting or being one of three equal parts into which anything is divided; as, the third part of a day. Third estate. In England, the commons, or the commonalty, who are represented in Parliament by the house of Commons. In France, the tiers etat. See Tiers etat. Third order See Third.
Origin: OE. Thirde, AS. Ridda, fr. Ri, reo, three; akin to D. Derde third, G. Dritte, Icel. Rii, Goth. Ridja, L. Tertius, Gr, Skr. Ttiya. See Three, and cf. Riding a jurisdiction, Tierce.