double talk

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Meaningless speech that consists of nonsense syllables mixed with intelligible words; gibberish.
• noun Deliberately ambiguous or evasive language.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic : Lying, especially in a formal political statement.
• noun idiomatic Speech which combines English and English-sounding gibberish for humorous effect.
• noun A simple phonetic code with a regular infix that makes meaningful speech sound unintelligible.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun deliberately unintelligible gibberish