veg·e·ta·ble 
(vĕjtə-bəl, vĕjĭ-tə-)
(vĕjtə-bəl, vĕjĭ-tə-)n.
1.
a. A plant cultivated for its edible parts, such as the roots of the beet, the leaves of spinach, the flower buds of broccoli, or the fruit or seeds of certain species, as beans, corn, and squash.
b. The edible part of such a plant.
c. A member of the vegetable kingdom, especially a green plant.
2. Offensive Slang One who is severely impaired mentally and physically, as by brain injury or disease.
adj.
1. Of, relating to, or derived from plants or a plant: vegetable dyes.
2. Made from or with edible plants or plant parts: vegetable lasagna.
3. Growing or reproducing like a plant.
[From Middle English, living and growing as plants do, from Old French, from Medieval Latin vegetābilis, from Late Latin, enlivening, from Latin vegetāre, to enliven, from vegetus, lively, from vegēre, to be lively; see weg- in the Appendix of Indo-European roots.]
Word History: Andrew Marvell's "To His Coy Mistress" contains many striking phrases and images, but perhaps most puzzling to modern readers is one in this promise from the speaker to his beloved: "Had we but world enough, and time ... / My vegetable love should grow / Vaster than empires and more slow." One critic has playfully praised Marvell for his ability to make one "think of pumpkins and eternity in one breath," but vegetable in this case is only indirectly related to edible plants. Here the word is used figuratively in the sense "having the property of life and growth, as does a plant," a use based on an ancient religious and philosophical notion of the tripartite soul. As interpreted by the Scholastics, the vegetative soul was common to plants, animals, and humans; the sensitive soul was common to animals and humans; and the rational soul was found only in humans. "Vegetable love" is thus a love that grows, takes nourishment, and reproduces, although slowly. Marvell's use in the 1600s illustrates the original sense of vegetable, first recorded in the 1400s. In the 1500s, the adjectival meaning of vegetable familiar to us, "having to do with plants," begins to appear, along with the first instances of vegetable as a noun meaning "a plant." It is not until the 1700s, however, that we find the noun and adjective used more restrictively to refer specifically to certain kinds of plants that are eaten.