| an elongated tubular extension of an epidermal cell of a root, serving to absorb water and minerals from the soil. |
| root hair n. A thin hairlike outgrowth of an epidermal cell of a plant root that absorbs water and minerals from the soil. |
| root hair
A hairlike outgrowth of a plant root that absorbs water and minerals from the soil. Root hairs are tubular extensions of the epidermis that greatly increase the surface area of the root. They are constantly dying off and being replaced by new ones as the root grows and extends itself into the soil. |