It's believed the name was given to the Ioway tribe, a group of Native Americans who lived in the region, by neighboring tribes. There are different theories about the origin of the nickname, including:
* They were considered "sleepy" because they lived in a peaceful area with little conflict.
* They were known for their relaxed nature and quiet demeanor.
* The name could be a metaphorical reference to their location on the banks of the Missouri River, a waterway known for its calm and peaceful waters.
Ultimately, the exact meaning of "Ioway" is still debated, but it's clear that it's a word with a rich history and cultural significance.