gibberish vs stuff and nonsense

gibberish

• Speech or writing that is unintelligible, incoherent or meaningless. 

• Needlessly obscure or overly technical language. 

• A language game, comparable to pig Latin, in which one inserts a nonsense syllable before the first vowel in each syllable of a word. 

• unintelligible, incoherent or meaningless 

stuff and nonsense

• rubbish, foolishness, poppycock