parity1

noun

• 1the state or condition of being equal, especially as regards status or pay:parity of incomes between rural workers and those in industrial occupations
• equivalent value of one currency in terms of another at an established exchange rate: the euro’s parity with the dollar [count noun]:an attempt to maintain exchange rate parities within the ERM

• 2 Mathematics (of a number) the fact of being even or odd.
• Physics the property of a spatial wave equation that either remains the same ( even parity) or changes sign ( odd parity) under a given transformation.
• Physics the value of a quantum number corresponding to parity.
• Computing a function whose being even (or odd) provides a check on a set of binary values.