The phrase "oat grain" refers to the small edible seeds of the oat plant. It is commonly used to make oatmeal, cereal, and other food products. Full definition
This finely ground oat locks in moisture and retains the soothing effects of the whole oat grain, relieving dry or irritated skin. (aveeno.com)
Researchers have found significant traces of oat grains on a stone pestle found in the cave, they report this week in the Proceedings of the National Academy of Sciences. (sciencemag.org)
Oatmeal is made of oats that have been removed from oat grain and dehulled. (healthyeating.sfgate.com)