This article researches the debatable issue in semasiology, particularly the origin of an idiom captured in four Slavic languages: Ukrainian zbyty z pantelyku, Russian sbit’ s pantalyku, Belarusian zbits’ z pantalyku, Polish zbić z pantałyku. The subject of analysis is fictional texts and lexicographical sources in which this phraseological unit first appeared. All etymological hypotheses developed by language experts during 19th-20th centuries were dedicated to the explanation of the word «pantelyk». The difficulty of revealing the figurative basis of the expression is due to the fact that this keyword does not belong to the Slavic vocabulary. This circumstance made it complicated to explain how the term «pantelyk» influenced the original figurative meaning of the idiom «seduce out of the right way». The new etymological version, offered by the article’s author, is that the idiom zbyty z pantelyku can be reconstructed as a semantic chain: throw off a course → seduce out of the right way → to throw into confusion → zbyty z pantelyku. The word «pantelyk», which wasn’t a part of any dialect, is a nonce formation or an occasional expression that emerged as a result of a burlesque travesty genre in the poem Eneyida by Ivan Kotlyarevsky.