Often indicates a disease, so it’s used in medical contexts to describe abnormal growths. The physician was concerned about the tubercle on the patient's skin.
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Plant Biology
In botany, a tubercle refers to natural bumps on plants and isn't necessarily harmful. The roots of the dahlia plant are full of small tubercles.
Pro Tip 3/3
Visual Indicator
Used to describe something you can see, usually in a scan or physical examination. On close inspection, multiple tubercles could be seen on the leaf's surface.