BULB

bulb. Bulb, n. a round root, as of tulips, onions, &c. a round beard

---

Bulb (bŭlb), n. [[L. bulbus, Gr. βολβόσ: cf. F. bulbe.]] 1. 1. (Bot.) A spheroidal body growing from a plant either above or below the ground (usually below), which is strictly a bud, consisting of a cluster of partially developed leaves, and producing, as it grows, a stem above, and roots below, as in the onion, tulip, etc. It differs from a corm in not being solid.
2. 2. (Anat.) A name given to some parts that resemble in shape certain bulbous roots; as, the bulb of the aorta.
Bulb of the eye, the eyeball. — Bulb of a hair, the “root,” or part whence the hair originates. — Bulb of the spinal cord, the medulla oblongata, often called simply bulb. — Bulb of a tooth, the vascular and nervous papilla contained in the cavity of the tooth. 3. 3. An expansion or protuberance on a stem or tube, as the bulb of a thermometer, which may be of any form, as spherical, cylindrical, curved, etc. Tomlinson.