What is "molecularity"

Molecularity \Mo*lec`u*lar"i*ty\, n. (Phys. & Chem.) The state of consisting of molecules; the state or quality of being molecular.

n. 1 (context uncountable English) The state of being molecular 2 (context chemistry English) (''of a reaction'') The number or molecules that react directly with one another

Molecularity in chemistry is the number of molecules that come together to react in an elementary reaction and is equal to the sum of stoicheometric coefficients of reactants in this elementary reaction. Depending on how many molecules come together, a reaction can be unimolecular, bimolecular or termolecular.