n. 1 a an underground fleshy-leaved storage organ of some plants (e.g. lily, onion) sending roots downwards and leaves upwards. b a plant grown from this, e.g. a daffodil. 2 = light-bulb (see LIGHT(1)). 3 any object or part shaped like a bulb.
[ L bulbus f. Gk bolbos onion ]