TARADIDDLE

THOMAS MCGREGOR: Wait, "taradiddle" isn't a word.
BEATRIX POTTER: Yes, it is. It means "fib," "pretentious nonsense."
THOMAS: That is exactly the sort of definition you'd make up for a made-up word.
BEA: Mr. McGregor, are you accusing me of taradiddling?

From the Peter Rabbit 2010s film