The state of being multiple or having multiple parts. The multiplicity of options available can sometimes be overwhelming.
A large number or variety. The city is known for its multiplicity of cultural events.
In mathematics, the number of times a particular root is repeated in a polynomial equation. The root x=2 has a multiplicity of 3 in the polynomial equation.
In high-energy physics, the number of particles produced in a single interaction or collision. The multiplicity observed in proton–proton collisions rises with increasing beam energy.