The term organic has different meanings (depending on the context):
In chemistry, "organic" refers to a chemical compound based
on a hydrocarbon, i.e. a chain or a ring of carbon atoms onto which hydrogen
atoms are bonded.
In agriculture, "organic" refers to a production system that
excludes or limits the use of chemicals
More:
In chemistry, the often used description 'based on living
things' is no longer appropriate since synthetic organic chemicals can now be
made. Millions of organic compounds are now known to man and the figure
continues to rise.
In agriculture, crop rotation and animal manure can be used
to maintain soil productivity in the place of fertilisers. Careful management
reduces the need for pesticides, nutritional supplements and medicines.