The word is jargon. It appeared in St. Petersburg after the arrival of the Persian embassy, which brought a gift - an elephant. It was in 1717. The elephant lived not long, about three years. Under Anna Ioanovna, new elephants were brought from India. So, there was no zoo, and the elephant was taken out to walk through the streets of the city. The elephant, a healthy, strong animal that could be used more efficiently than a horse, walked without a deed - elephant. A new word was born. The word "elephant" is an ethymon in relation to the word "sleep". It was this theme that lay at the base of Krylov’s fairy tale “The Elephant and Moska.”