Have you heard of dihydrogen monoxide? It's in tons of products from soft drinks to bug sprays and even in baby food. It's one of the most caustic substances known to man and will eventually break down metal or rock if left in contact long enough.
When I was about 12, Jake "the Snake" Roberts was a scary, scary man. His finishing move, the DDT, was the most devastating maneuver in professional wrestling. He would tuck your neck under his arm, then drive your forehead into the mat.
An eponymous disease is a disease named after someone. Names tend to be known better than the scientifically descriptive name and are usually the way physicians refer to the disease when talking with patients or clients. Thus, amyotrophic lateral sclerosis is known as Lou Gehrig's disease.