It's a gloriously weird nonsense poem by Lewis Carroll, who wrote "Alice in Wonderland" and made up all the funky words in the poem. He defined the words in the first verse, but the rest mean whatever you think they ought to mean by context. It's also wonderfully fun to read out loud -- it just gallops along, and by the time you get to the end you really don't care what "uffish" means. Try it!