At one point "Split an atom" was by definition nonsensical because atoms were conceived of as the smallest, unsplittable bits of matter. But then we found out

At one point "Split an atom" was by definition nonsensical because atoms were conceived of as the smallest, unsplittable bits of matter. But then we found out that we could split these pieces of matter we'd mistakenly called "atoms" and rather than renaming them we just changed the definition of "atom" to correspond to what we'd always been calling "atoms". In practice I don't think this was unreasonable and I wouldn't strongly object to doing the same with what we've been calling "The universe".