The article discusses the etymology of the Greek theonym Κρόνος (Cronus), qualified by all dictionaries as etymologically unclear. I argue that this name can be considered as a member of the small class of nouns in -όνο- with agent-instrumental semantics. Following an old proposal by H. D. Müller (later advocated by M. Janda), I adopt the analysis of this name as a derivative of the verbal root *κερ‑ (cf. κείρω ‘cut’, Arm. kʻerem ‘scratch, rub’, Old Norse skera ‘cut’, etc.), thus explaining the name of the harvest god Cronus as ‘the one who cuts; castrator’, referring to one of his main functions as well as to the myth of castration of his father Uranus by Cronus. The class of nouns in ‑όνο‑ (/ f. ‑ονη) arguably includes such nouns as θρ‑όνο‑ς ‘seat, chair’ (analysable as a derivative of *θερ‑ < PIE *dʰer‑ ‘fix, hold’), κλ‑όνο‑ς ‘excitement, throng’, φθ‑όνο‑ς ‘malice, envy’ (PIE *dʰegʷʰ‑ ‘almost reach’), βελ‑όνη ‘needle’ (PIE *gʷel‑ ‘throw, pierce’); ἀκ‑όνη ‘whetstone’ (PIE *h₂eḱ‑ ‘sharp(en)’). Possible correspondences of this morphological type outside Greek may include the Celtic type in ‑ono/ā‑ (cf. Nechtan, Mātronā) and Indo‑Iranian formations in ‑āna‑ of the type yudhāna‑ ‘enemy’ (yudh ‘fight’) or budhāna‑ ‘sage, teacher’ (budh ‘awake; observe, perceive’), formally coinciding with the middle participles made from root stems and, probably, partly absorbed by them.