What's the Definition of Organic?

What does the term "organic" mean to farmers, manufacturers, and the USDA? I thought this label reflected an agricultural process of growing foods free from pesticides, herbicides, and other synthetic chemicals. Since reading the Omnivore's Dilemma, I've applied this term to rearing livestock free from antibiotics, hormones, and other chemicals.

Yet, the "organic" label may be changing. If the USDA passes a new set of regulations, 38 substances that have been previously banned from the National List of Allowed and Prohibited Substances, will be included in the "organic" category.

To read more about the organic-label issue, go to the USDA website here. I also found another helpful blog that discusses this issue in greater detail.