Where does “κλειδί” come from?

κλειδί (Greek) comes from Byzantine Greek κλειδίν, from Ancient Greek κλειδίον, from Old Georgian კლიტჱ, from Ancient Greek κλείς, from Proto-Hellenic klāwī́ds, from Proto-Indo-European kleh₂u- — nail, pin, hook - instruments, of old use for...

κλειδί (Greek): key; spanner