If a vellus hair is stimulated to grow deeper and coarser, it is referred to as:

When a vellus hair is stimulated to grow deeper and coarser, it undergoes a transformation into a different type of hair. This process is typically referred to as "modified terminal hair." In the context of hair growth, vellus hairs are fine, thin, and light-colored, while terminal hairs are thicker, darker, and longer.

During hormonal changes, or as a response to certain stimuli, vellus hair can transition into a form of terminal hair. This change signifies that the hair has transitioned into a more mature state, characterized by increased thickness and depth.

Understanding this transformation is crucial in electrolysis and hair removal practices, as it helps practitioners diagnose and treat hair growth issues effectively. Recognizing that vellus hair can evolve into terminal hair provides insight into the biology of hair and the factors influencing its characteristics.