PARITY

n. 1 equality or equal status, esp. as regards status or pay. 2 parallelism or analogy (parity of reasoning). 3 equivalence of one currency with another; being at par. 4 (of a number) the fact of being even or odd. 5 Physics (of a quantity) the fact of changing its sign or remaining unaltered under a given transformation of coordinates etc. [F parit÷ or LL paritas (as PAR(1))]