Earlier quoted context omitted.
Much like saying "murder is wrong", the wrongness is a part of the definition of the word. There's no need for evidence or logic, beyond understanding what a definition is.
Neither rape nor murder are inherently, definitionally wrong. There are situations in extremis where murder and rape are considered justifiable: in war, murder is often praised; and in an "everyone else is dead, humanity will go extinct" situation (e.g. the subjective belief of Lot's daughters, according to some traditions, in Genesis 19:31–36), rape might¹ be considered permissible. And both words are used to refer…
> in war, murder is often praised;
The killing of an enemy combatant, for example, is usually lawful, praised and not considered murder. Generally speaking, the killing of a civilian is sometimes a war crime and considered a murder.
You also have a lot to say on the nuanced ethics of killing and on sexual violence, but these deal with the underlying concepts themselves and the words don't matter; in fact philosophers frequently give common terms a specialized, ad-hoc definition when they want to discuss these concepts themselves.