Third (?), n.

1. The quotient of a unit divided by three; one of three equal parts into which anything is divided.

2. The sixtieth part of a second of time.

3. (Mus.) The third tone of the scale; the mediant.

4. pl. (Law) The third part of the estate of a deceased husband, which, by some local laws, the widow is entitled to enjoy during her life.

Major third (Mus.), an interval of two tones. -- Minor third (Mus.), an interval of a tone and a half.

Third (thẽrd), a. [OE. thirde, AS. þridda, fr. þrī, þreó, three; akin to D. derde third, G. dritte, Icel. þriði, Goth. þridja, L. tertius, Gr. tri`tos, Skr. tṛtīya. See Three, and cf. Riding a jurisdiction, Tierce.]

1. Next after the second; coming after two others; -- the ordinal of three; as, the third hour in the day. "The third night." Chaucer.

2. Constituting or being one of three equal parts into which anything is divided; as, the third part of a day.

Third estate. (a) In England, the commons, or the commonalty, who are represented in Parliament by the House of Commons. (b) In France, the tiers état. See Tiers état. Third order (R. C. Ch.), an order attached to a monastic order, and comprising men and women devoted to a rule of pious living, called the third rule, by a simple vow if they remain seculars, and by more solemn vows if they become regulars. See Tertiary, n., 1. -- Third person(Gram.), the person spoken of. See Person, n., 7. -- Third sound. (Mus.) See Third, n., 3.

-- Webster's unabridged 1913