Rate of consumption of monomers in a chain polymerization, or the rate of consumption of the functional groups in the reaction mixture of a polycondensation or polyaddition.
Source: PAC, 2008, 80, 2163. (Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization (IUPAC Recommendations 2008)) on page 2183 [Terms] [Paper]