1. (noun)parity, para (obstetrics) the number of liveborn 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"
2. (noun)parity (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 "parity is often used to check the integrity of transmitted data"
4. (noun)parity, conservation of parity, space-reflection symmetry, mirror symmetry (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