Final answer:
The compulsion often associated with an obsession with germs or fear of germs is Cleaning, which is part of the OCD spectrum where excessive behaviors are performed to ease the distress caused by such obsessions.
Step-by-step explanation:
The compulsion that is usually associated with obsessions with germs, fear of germs, or contaminants is Cleaning. People with a fear of germs or contaminants may engage in excessive cleaning or washing behaviors to alleviate their anxiety about contamination. This is a classic manifestation of a type of Obsessive-Compulsive Disorder (OCD), where the obsessions are the persistent and unwanted thoughts about germs, whereas the compulsions are the behaviors performed to ease the distress caused by these thoughts. It's worth noting a comprehensive germ theory helps understand how diseases spread and why cleanliness is important for health, but OCD related to germs is a psychological condition that often requires medical intervention.