Are the words canker and chancre interchangeable?

The words "canker" and "chancre" are not interchangeable. They have different meanings and origins.

Canker is a general term that can refer to any of several types of sores or ulcers that occur on the skin, mouth, or other mucous membranes. Cankers are typically small, round, and painful, and they can be caused by a variety of factors, including infection, trauma, and certain medical conditions.

Chancre, on the other hand, is a specific type of sore that is caused by syphilis, a sexually transmitted infection (STI). Chancres typically appear on the genitals or other areas of the body that have come into contact with infected tissue. They are usually larger and more painful than cankers, and they can be accompanied by other symptoms of syphilis, such as fever, rash, and swollen lymph nodes.

Therefore, while cankers and chancres may both be sores, they are not the same thing and they should not be used interchangeably.