At or near the bottom of lists of different types of millets you may see something called "Job's tears," "adlay," "adlay millet," or sometimes "Chinese barley" (species name Coix lacryma-jobi). Here's a quick primer from someone who has only recently paid attention to it (but has not yet encountered it as food or crop).

Botanically it is closer to sorghum and corn (maize) than it is to the other millets (and not close to barley, which is in the same sub-family as wheat). It grows to similar heights as corn or sorghum, and its seeds are larger than sorghum (itself larger than all the other millets). A native of southeast Asia, it is a minor crop in several countries of Asia. I have no information about it being grown at all in North America, and it certainly is not a significant field crop anywhere in this region.

A more detailed discussion of its uses as food and for beverages can be read in a 2016 article by Marguerite Preston in Bon appétit, entitled "The Next Cult Gluten-Free Grain: Job's Tears"