cornmeal (n.)

"grain," Old English corn "single seed of a cereal plant; seeds of cereal plants generally; plants which produce corn when growing in the field," from Proto-Germanic *kurnam "small seed" (source also of Old Frisian and Old Saxon korn "grain," Middle Dutch coren, German Korn, Old Norse korn, Gothic kaurn), from PIE root *gre-no- "grain."

The sense of the Old English word was "grain with the seed still in" (as in barleycorn) rather than a particular plant. Locally understood to denote the leading crop of a district. It has been restricted to the indigenous "maize" in America (c. 1600, originally Indian corn, but the adjective was dropped), usually "wheat" in England, "oats" in Scotland and Ireland, while Korn means "rye" in parts of Germany.

Maize was introduced to China by 1550, it thrived where rice did not grow well and was a significant factor in the 18th century population boom there. Corn-starch is from 1850. Corn-silk is attested from 1852.

"the edible part of ground grain;" Middle English mēle, from Old English melu, from Proto-Germanic *melwan "grind" (source also of Old Frisian mele "meal," Old Saxon melo, Middle Dutch mele, Dutch meel, Old High German melo, German Mehl, Old Norse mjöl "meal;" literally "what is ground;" Old Saxon, Old High German, Gothic malan, German mahlen "to grind"), from PIE root *mele- "to crush, grind." The verb form is not found in Old English. Forms with an -a- begin in late Middle English. "Now commonly understood to exclude the product of wheat (this being called FLOUR)" [OED].