Webster's Revised Unabridged Dictionary · 1913

Cereal

Cereal , adjective

[Latin Cerealis pert. to Ceres, and hence, to agriculture. See Ceres.]

Of or pertaining to the grasses which are cultivated for their edible seeds (as wheat, maize, rice, etc.), or to their seeds or grain.

Cereal , noun

Any grass cultivated for its edible grain, or the grain itself; -- usually in the plural.