parity

Short definition from Wiktionary

Noun

1. 1
   Equality; comparability of strength or intensity.
2. 2
   Senses related to classification into two sets: A set with the property of having all of its elements belonging to one of two disjoint subsets, especially a set of integers split in subsets of even and odd elements.
3. 3
   Senses related to classification into two sets: The classification of an element of a set with parity into one of the two sets.
4. 4
   Senses related to classification into two sets: The count of one bits in a value, reduced to even or odd or zero or one.
5. 5
   Senses related to classification into two sets: Symmetry of interactions under spatial inversion.
6. 6
   In reversi, the last move within a given sector of the board.
7. 7
   Resemblance; analogy.
8. 8
   The number of delivered pregnancies reaching viable gestational age, usually between 20-28 weeks.
9. 9
   The number of times a sow has farrowed.