The outer covering of many foodgrains; examples are the horny covering (as in cottonseeds), leathery skin (as in sesame seeds) or parchment-like coating (as in soyabeans). This is removed when edible protein products are to be made from these oilseeds.
An exterior layer, typically parched; in addition, the process of eliminating said layer. However, to “hull” corn implies the extraction of kernels from the cob.