Darth Vader's name was changed to Lord Fener in Italy because Vader sounds too much like the Italian word for toilet.

Is There Proof that “Vader” was Changed to “Fener” Because Vader Sounds Like “Toilet”?

In Italian “vaso” means “bowl” and can refer to “toilet bowel”, likewise “water” (pronounced “vater”) has the same connotation. This is likely the reason Darth Vader’s named was changed from Lord Vader to Lord Fener in the Italian version of Star Wars due to this.

As an Italian speaking reader confirmed, “Lord Vader” would have sounded “extremely ridiculous”.

Although the official reason for the name change can’t be confirmed, the translation itself is easily confirmed (see the Italian Wiki page on “water”). [1]

Thus, it is very likely this was the reason for the name change. So despite any official proof, the claim can be characterized as a fact.

Did Other Star Wars Characters Get Name Changes?

Other Star Wars characters also had their names changed (for example Jabba the Hutt becomes Jabba le Forestier, Jabba the forester, in French), and of course translating the movie meant translating famous lines like [spoiler alert], “Luke, I am your Father” (as illustrated by the video below).