Source : Webster's Revised Unabridged Dictionary (1913)

Parity \Par"i*ty\, n. [L. paritas, fr. par, paris, equal: cf. F.
   parit['e]. See {Pair}, {Peer} an equal.]
   The quality or condition of being equal or equivalent; A like
   state or degree; equality; close correspondence; analogy; as,
   parity of reasoning. ``No parity of principle.'' --De
   Quincey.

         Equality of length and parity of numeration. --Sir T.
                                                  Browne.

Source : WordNet®

parity
     n 1: (obstetrics) the number of live-born children a woman has
          delivered; "the parity of the mother must be
          considered"; "a bipara is a woman who has given birth to
          two children" [syn: {para}]
     2: (mathematics) a relation between a pair of integers: if both
        integers are odd or both are even they have the same
        parity; if one is odd and the other is even they have
        different parity
     3: (computer science) abit that is used in an error detection
        procedure in which a 0 or 1 is added to each group of bits
        so that it will have either an odd number of 1's or an
        even number of 1's; e.g., if the parity is odd then any
        group of bits that arrives with an even number of 1's must
        contain an error [syn: {parity bit}, {check bit}]
     4: (physics) parity is conserved in a universe in which the
        laws of physics are the same in a right-handed system of
        coordinates as in a left-handed system [syn: {conservation
        of parity}, {space-reflection symmetry}, {mirror symmetry}]
     5: functional equality

Source : Free On-Line Dictionary of Computing

parity
     
         An extra bit added to a {byte} or
        {word} to reveal errors in storage (in {RAM} or {disk}) or
        transmission.  Even (odd) parity means that the parity bit is
        set so that there are an even (odd) number of one bits in the
        word, including the parity bit.  A single parity bit can only
        reveal single bit errors since if an even number of bits are
        wrong then the parity bit will not change.  Moreover, it is
        not possible to tell which bit is wrong, as it is with more
        sophisticated {error detection and correction} systems.
     
        See also {longitudinal parity}, {checksum}, {cyclic redundancy
        check}.
     
        (1996-03-01)