n. [ L. bulbus, Gr. bolbo`s: cf. F. bulbe. ] 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. [ 1913 Webster ]

2. (Anat.) A name given to some parts that resemble in shape certain bulbous roots; as, the bulb of the aorta. [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

3. a light bulb. [ 1913 Webster ]

v. i. To take the shape of a bulb; to swell. [ 1913 Webster ]

a. [ L. bulbaceus. See Bulb, n. ] Bulbous. Jonson. [ 1913 Webster ]

a. Of or pertaining to bulb; especially, in medicine, pertaining to the bulb of the spinal cord, or medulla oblongata; as, bulbar paralysis. [ 1913 Webster ]

a. Having a bulb; round-headed. [ 1913 Webster ]

n. [ Dim., fr. bulb, n. ] (Bot.) A separable bulb formed on some flowering plants. [ 1913 Webster ]

a. [ Bulb, n.+ -ferous: cf. F. bulbifère. ] (Bot.) Producing bulbs. [ 1913 Webster ]

n. [ Dim. fr. bulb. ] 1. (Bot.) A small or secondary bulb; hence, now almost exclusively: An aërial bulb or deciduous bud, produced in the leaf axils, as in the tiger lily, or relpacing the flowers, as in some onions, and capable, when separated, of propagating the plant; -- called also bulblet and brood bud. [ Webster 1913 Suppl. ]

2. (Anat.) A small hollow bulb, such as an enlargement in a small vessel or tube. [ Webster 1913 Suppl. ]

n. [ Bulb, n.+ -let. ] (Bot.) A small bulb, either produced on a larger bulb, or on some aërial part of a plant, as in the axils of leaves in the tiger lily, or replacing the flowers in some kinds of onion. [ 1913 Webster ]

a. Bulbous. [ 1913 Webster ]

n. [ Bulb, n.+ tuber. ] (Bot.) A corm. [ 1913 Webster ]

a. [ L. bulbosus: cf. F. bulbeux. See Bulb, n. ] Having or containing bulbs, or a bulb; growing from bulbs; bulblike in shape or structure. [ 1913 Webster ]

‖n. [ Per. ] (Zool.) The Persian nightingale (Pycnonotus jocosus). The name is also applied to several other Asiatic singing birds, of the family Timaliidæ. The green bulbuls belong to the Chloropsis and allied genera. [ Written also buhlbuhl. ] [ 1913 Webster ]

n. [ L. bulbulus, dim. of bulbus. See Bulb, n. ] A small bulb; a bulblet. [ 1913 Webster ]

n. a lamp for providing intense momentary light to take a photograph.
Syn. -- flash, photoflash, flash lamp, flashgun. [ WordNet 1.5 ]

{ }. (Internal-combustion Engines) See Semi-diesel, below. [ Webster 1913 Suppl. ]

n. A glass bulb with metallic contacts on the outside connected to a wire filament (usually tungsten) inside that emits light when heated by passage of electricity through the filament; -- used as the replaceable light-emitting component of an electric lamp, flashlight, lighting fixture, etc.
Syn. -- light bulb, bulb, incandescent lamp, electric light, electric-light bulb. [ WordNet 1.5 +PJC ]

n. [ Pseudo- + bulb. ] (Bot.) An aërial corm, or thickened stem, as of some epiphytic orchidaceous plants. [ 1913 Webster ]

. (Physics) That one of the two similar thermometers of a psychrometer the bulb of which is moistened; also, the entire instrument. [ Webster 1913 Suppl. ]