The IUPAC salt definition is: "A chemical compound consisting of an assembly of cations and anions" (Compendium of Chemical Terminology Gold Book, Version 2.2.3, 2014)

So it means that a base like NaOH, that's also an ionic crystal, is a salt? I'm quite certain it's not but it seems the definition says so.

Then, a if a base is not a salt, what would be a better definition for salt?