The word "shanker" is often used informally to refer to a sore on the skin, usually caused by a skin infection or an STD. However, there are several synonyms you can use instead of "shanker" to sound more professional or avoid using the word altogether. Some options include "ulcer," "lesion," "sore," "abscess," "pustule," or "blister." These words can be used in medical or dermatological contexts to describe symptoms or conditions without using colloquial or potentially stigmatizing language. When in doubt, it's always best to consult a medical professional rather than self-diagnose or use informal terminology.