To most of us, "whole grain" means that a physical process--like crushing or grinding--
has not removed any of the nutrients contained in the entire grain seed.
"Following is the official definition of whole grains, approved and endorsed by the Whole Grains Council in May 2004:
Whole grains or foods made from them contain all the essential parts and naturally-occurring nutrients of the entire grain seed. If the grain has been processed (e.g., cracked, crushed, rolled, extruded, and/or cooked), the food product should deliver approximately the same rich balance of nutrients that are found in the original grain seed.
This definition means that 100% of the original kernel – all of the bran, germ, and endosperm – must be present to qualify as a whole grain."
Definition of Whole Grains | The Whole Grains Council