The Gemini AI says:
The term "gobbledygook" was coined in 1944 by Maury Maverick, a congressman from Texas.
During World War II, Maverick was the chairman of the Smaller War Plants Corporation. Frustrated with the excessively long, vague, and pompous language of bureaucratic memos, he issued a memorandum to his staff telling them to "stay off gobbledygook language." He defined it as "talk or writing which is long, pompous, vague, involved, usually with Latinized words."
Maverick explained that he came up with the word by thinking of the sound a turkey makes—a "gobbledygobbling" sound. He felt that the pretentious and convoluted language of officialdom sounded just as ridiculous as a turkey's gobble.