Kyrgyz ethnonym, which is considered the oldest ethnonym among Turkic ethnonyms, has been studied so far and various assumptions have been made. Today, the majority of scholars accept the assumption that this ethnonym is composed of the number noun kyrk ‘forty’ and the plural suffix +z, meaning a people of forty tribes and a nation of forty parts. But this assumption has very serious biases. For example, in ancient Turkic ethnonyms, there was no ethnonym with the number forty, while ethnonyms with numbered names such as uch karluk, on ok, toguz oguz, etc. have a noun as well as a number. Most importantly, when we make a morphological analysis of the ancient forms of the Kyrgyz ethnonym in Chinese sources such as Kyrkun/Kyrkur/Kyrkut/Kyrkuz, we see that the origin of the word is not the number kyrk ‘forty’, but the word kyrku. In historical Turkic languages, the word "kyrku" means predator bird, eagle. Therefore, in this article, we have proposed a new explanation of the origin of the Kyrgyz ethnonym.

The Kyrgyz ethnonym, the root kyrku, an eagle, Kyrgyday, plural suffix