nu·mer·os·i·ty \ˌn(y)üməˈräsəd.ē\noun (-es) Etymology: Middle French numerosité numerousness, from Late Latin numerositat-, numerositas, from Latin numerosus numerous + -itat-, -itas -ity 1.: numerousness < the earliest scales of measurement were scales of numerosity — scales for the counting of pebbles or cattle or warriors — S.S.Stevens > 2.archaic: melodic flow : rhythm