Which term represents the combining form for swelling or edema?

The term that represents the combining form for swelling or edema is indeed "edem/o". Combining forms in medical terminology often consist of a root word and a vowel, which allows them to integrate with other words. The root "edema" specifically refers to excess fluid that accumulates in the body tissues, leading to swelling.

Using "edem/o" as a combining form correctly communicates concepts related to swelling, making it essential in various medical contexts, such as describing conditions like peripheral edema or pulmonary edema. This understanding is key when studying medical terminology related to anatomy and pathology.

The other options represent different root terms: "hist/o" refers to tissue, "thyr/o" pertains to the thyroid gland, and "py/o" is associated with pus. Each of these terms is pertinent to specific medical contexts, which distinguishes them from the focus on swelling that "edem/o" provides.