Fiber
FI'BER, noun [Latin fibra.]
1. A thread; a fine, slender body which constitutes a part of the frame of animals. Of fibers, some are soft and flexible; others more hard and elastic. Those that are soft are hollow, or spungy and full of little cells, as the nervous and fleshy. Some are so small as scarcely to be visible; others are larger and appear to be composed of still smaller fibers. These fibers constitute the substance of the bones, cartilages, ligaments, membranes, nerves, veins, arteries, and muscles.
2. A filament or slender thread in plants or minerals; the small slender root of a plant.
3. Any fine, slender thread.