Which suffix means "inflammation"?

The suffix that means "inflammation" is indeed "-itis." This suffix is commonly used in medical terminology to denote inflammatory conditions affecting specific organs or systems. For instance, appendicitis refers to the inflammation of the appendix, and hepatitis refers to inflammation of the liver.

In contrast, "-ology" refers to the study of a particular subject, "-ectomy" indicates surgical removal of a part, and "-osis" denotes a condition or process, often implying a disease or abnormal state. Therefore, these other suffixes do not convey the meaning of inflammation, making "-itis" the correct choice for indicating inflammatory conditions in medical contexts.