"A vector is a thing with both magnitude and direction" isn't really a good definition. Cars have both -- an SUV is larger than a sedan, establishing a magnitude, and they obviously point in a direction -- but I don't think anyone would mistake them for pointy arrow vectors. If you use the more rigorous definition that a vector is an element of a space that obeys the vector space axioms it becomes easier to invert a vector "semantically" (a thing that doesn't obey the axioms) but quite a bit less useful. Cats don't obey the axioms, nor do punctuation marks.