1) Feed corn grown for stock 
Field corn is maize of varieties that (in contrast with sweet corn) are not, in the United States, grown primarily for consumption as human food in the form of fresh kernels. While popcorn is not grown for human consumption in form of fresh kernels, it is not considered to be field corn. More than 98% of corn-growing land in the U.S. is in use for...
Any variety of corn that is grown extensively in large fields primarily for livestock feed, as contrasted with the horticultural varieties, such as sweet corn or popcorn. Most field corn is of the dent variety. 
[n] - corn grown primarily for animal feed or market grain
noun corn grown primarily for animal feed or market grain
feed corn grown for stock.