bulb /ˈbəlb/ 名詞
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. 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. 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.
3. a light bulb.
Bulb, v. i. To take the shape of a bulb; to swell.
n 1: a modified bud consisting of a thickened globular
underground stem serving as a reproductive structure
2: electric lamp consisting of a glass bulb containing a wire
filament (usually tungsten) that emits light when heated
[syn: light bulb, lightbulb, incandescent lamp, electric
light, electric-light bulb]
3: a rounded part of a cylindrical instrument (usually at one
end); "the bulb of a syringe"
4: lower or hindmost part of the brain; continuous with spinal
cord; (`bulb' is an old term for medulla oblongata); "the
medulla oblongata is the most vital part of the brain
because it contains centers controlling breathing and
heart functioning" [syn: medulla oblongata, medulla]
5: a rounded dilation or expansion in a canal or vessel or