Light bulb, a source of electric lighting.
Flashbulb, a bright, rapid lightbulb.
Bulb (photography), a shutter setting.
Bulbous bow, a protruding bulb at the bow below the waterline
Bulb keel, a term in naval architecture.
Bulb magazine, a
Bulbs (song), a 1974 song by Van Morrison
As an abbreviation, Bulb is short for the orchid genus Bulbophyllum.