Which suffix refers to a tumor or swelling?

The suffix that refers to a tumor or swelling is indeed "-oma." This suffix is commonly used in medical terminology to denote various types of tumors, both benign and malignant. For instance, "carcinoma" refers to a cancerous tumor arising from epithelial tissue, while "lipoma" refers to a benign tumor composed of fatty tissue.

In contrast, other suffixes serve different purposes: "-omy" typically refers to surgical procedures involving an incision, "-pathy" indicates a disease or disorder, and "-itis" denotes inflammation of an organ or tissue. Thus, "-oma" is specifically associated with tumors and swelling, making it the correct choice in this context. Understanding these distinctions is crucial in medical terminology, aiding clear communication in healthcare settings.