From BiblePortal Wikipedia

King James Dictionary [1]

Third a. thurd. L. tertius. The first after the second the ordinal of three. The third hour in the day among the ancients, was nine o'clock in the morning.

Third estate, in the British nation, is the commons or in the legislature, the house of commons.

Third order, among the Catholics,is a sort of religious order that observes the same rule and the same manner of life in proportion as some other two orders previously instituted as the third order of Franciscans, instituted by St. Francis in 1221.

Third point or tierce point, in architecture,the point of section in the vertex of an equilateral triangle.

Third rate, in navies. A third rate ship carries from 64 to 80 guns.

Third sound, in music. See the noun Third.

THIRD, n. thurd. The third part of any thing. A man takes land and tills it for one third of the produce the owner taking two thirds.

1. The sixtieth part of a second of time. 2. In music, an interval containing three diatonic sounds the major composed to two tones, called by the Greeks ditone, and the minor called hemiditone, consisting of a tone and a half.

Webster's Dictionary [2]

(1): ( a.) Next after the second; coming after two others; - the ordinal of three; as, the third hour in the day.

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

(3): ( n.) The quotient of a unit divided by three; one of three equal parts into which anything is divided.

(4): ( n.) The sixtieth part of a second of time.

(5): ( n.) The third tone of the scale; the mediant.

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

Wilson's Dictionary of Bible Types [3]

(See under "THREE").

International Standard Bible Encyclopedia [4]

thûrd ( שׁלישׁי , shelı̄shı̄  ; τρίτος , trı́tos ):   Isaiah 19:24 , "In that day shall Israel be the third with Egypt and with Assyria," etc., brings out very distinctly the universal and missionary character of Isaiah's prophecies and of Israel's destiny (compare  Ezekiel 16:63; and see G. A. Smith, Isaiah , II, 275, 278; Watkinson, The Blind Spot 21 ff).

For "third hour," "third month," "third year," see Calendar; Day; Time .