Answer:
In Through the Looking Glass, Humpty Dumpty tells Alice that a rath is "a sort of green pig". However, in an earlier publication, Carroll described a rath as "a species of land turtle. Head erect, mouth like a shark, the front fore legs curved out so that the animal walked on its knees, smooth green body, lived on swallows and oysters."
Much of the point of Jabberwocky, is that it is comprised of meaningless nonsense words, and the definition of them is irrelevant. Carroll's inconsistency of definition demonstrates this, so it is just as valid to ascribe the words with your own meanings as it is to adhere to Carroll's.