Leprously is an adverb that describes something done in a manner that resembles the symptoms of leprosy, a chronic infectious disease. While not a commonly used term, there are a few synonyms that can be used in its place: diseasedly, contagiously, or infectiously. These words all describe something done in a manner that suggests the spread of disease or an unhealthy condition. Alternatively, one could use "gangrenously," which suggests the decay and rotting of tissue, or "decadently," which implies moral decay or decline. It is important to choose the appropriate synonym based on the context in which it is being used.