Complex sentence: Atsina is thought to be a Blackfoot word for "gut people", the other Arapaho who considered them inferior called them "Hitúnĕna", meaning "beggars".
Split into simpler sentences: Atsina is thought to be a Blackfoot exonym, meaning "gut people". The Arapaho, who considered them inferior, called them "Hitúnĕna", meaning "beggars".