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.