Uninfectious refers to something that is not capable of causing an infection or contagion. There are several synonyms that can be used to describe this term, including non-infectious, sterile, hygienic, uncontaminated, and clean. Non-infectious is often used in medical contexts to describe diseases or conditions that are not caused by a pathogen. Sterile and hygienic both suggest a state of cleanliness or purity, while uncontaminated implies that the object or area in question has not been exposed to harmful bacteria or viruses. Clean can be used to describe both physical and metaphorical cleanliness, such as a clean bill of health or a clean environment.