A disease in which the body produces antibodies that attack its own tissues, leading to the deterioration and in some cases to the destruction of such tissue. In simpler terms, it is when your immune system...is...bad.
Ayesha had to start taking medication when she got rheumatoid arthritis, a type of autoimmune disease.
A curtisbeard is facial hair that is too long to be called stubble, but is too short to be called a real beard. This gives the face a fuzzy appearance. This term derives its name from the middle school/high school teacher Mr. Curtis, who can nearly always be seen with this kind of facial hair.
After not shaving for a week and a half, Andrew had a curtisbeard.