What is another term for a state of decaying matter?

The correct answer is putrefy, which refers to the process of decaying or rotting organic matter. When matter undergoes putrefaction, it breaks down due to the action of bacteria, fungi, and other microorganisms. This term captures not only the idea of decay but also the associated odors and chemical changes.

Prolific, while it refers to something that produces abundantly or is highly fruitful, does not relate to decay at all. Rectitude pertains to moral integrity and righteousness, which is irrelevant to the context of decay. Quay is a structure where ships dock and does not connect to the concept of decaying matter. Therefore, putrefy is precisely the term that describes this state of decomposition.