jabberwock

n. gibberish, nonsensical speech

"Jabberwocky" is a poem of nonsense verse written by Lewis Carroll, and found as a part of his novel Through the Looking-Glass, and What Alice Found There (1871). It is generally considered to be one of the greatest nonsense poems written in the English language. This poem is used in many schools to teach students about the use of portmanteaux.
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[Folklore] The Jabberwock is the eponymous central figure in a strange, almost gibberish poem by Lewis Carroll, called "The Jabberwocky", which appeared in Through the Looking-glass. It was represented as a dragon-like creature by Sir John Tenniel, who did the illustrations for Carroll's Through the Looking Glass and Alice in Wonderland.