Which of the following roots means 'normal'?

• A. nephr/o
• B. odont/o
• C. norm/o
• D. natr/o

Answer: (C)

Understanding medical word parts that convey basic meanings helps you identify what a term is saying. The root that means "normal" is norm/o. This combining form signals standard or typical condition, and you’ll see it in terms like normocephalic (head of normal size) or normotensive (normal blood pressure). The other roots have different meanings: nephr/o refers to the kidney, as in nephrology or nephritis; odont/o refers to a tooth, as in orthodontist or odontoplasty; and natr/o relates to salt or sodium, used in terms about sodium balance in the body. So the root that denotes normal is norm/o.