- Parity
- Parity Par"i*ty, n. [L. paritas, fr. par, paris, equal: cf. F.
parit['e]. See {Pair}, {Peer} an equal.]
1. The quality or condition of being equal or equivalent; a
like state or degree; equality; equivalence; close
correspondence; analogy; as, parity of reasoning. ``No
parity of principle.'' --De Quincey.
[1913 Webster]
Equality of length and parity of numeration. --Sir T. Browne. [1913 Webster]

2. Specifically: (Finance) Equivalence in value to the currency of another country. [PJC]

3. (Physics) A property assigned to elementary particles, conceptualized as a form of symmetry, representing the fact that no fundamental distinctions can be observed between right-handed and left-handed systems of particles in their interactions, and supported by the typical observation that the total parity of a system is unchanged as particles are created or annihilated; however, certain interactions involving the weak force have been shown to violate the principle of conservation of parity. [PJC]

4. (Physics) A property of the wave function of a system, which takes the value of +1 or -1, indicating whether the value of the wave function changes sign if each of the variables of the system is replaced by its negative. [PJC]

5. (Med.) The condition of having borne a child or children, alive or dead. [PJC]

6. (Math.) The property of being even or odd; as, 3 has odd parity, but 6 has even parity. [PJC]

7. Hence: (Computers) The property of having an even or odd number of bits set to the value of 1 (as opposed to 0); -- applied to bytes or larger groups of bits in a data structure. It is used mostly in the process of {parity checking}. The parity of a data structure can be changed by changing the value of the {parity bit}. [PJC]

*The Collaborative International Dictionary of English.
2000.*