Q: I just saw the expression “to tell tales out of work” on a website, which inspired me to look up the original. To my surprise, I had been using “to tell tales out of school” incorrectly all my life. I thought it meant to tell a tall tale, but I now see that it means to reveal confidential information. My question is: where does this expression come from and why “out of school”?
A: The expression “to tell tales out of school” is an old one, dating back to at least the 16th century, and probably earlier.
The first published reference in the Oxford English Dictionary is from a 1546 book of proverbs and epigrams collected by the English writer John Heywood: “To tell tales out of schoole, that is hir great lust.”
The OED defines it as meaning “to betray damaging secrets,” but it doesn’t explain the origin of the expression.
However, the Penguin Dictionary of English Idioms explains that “in this context ‘out of school’ means after class, when the tale-bearer has the opportunity to speak to the teacher alone.”
A 1579 citation, from a book of literary criticism by Stephen Gosson, seems to support the schoolhouse origin of the expression:
“I shoulde tel tales out of the Schoole, and bee Ferruled for my faulte, or hyssed at for a blab, yf I layde al the orders open before your eyes.”
The Penguin idiom dictionary defines the expression as “to talk maliciously about a person’s private affairs behind his back,” but I generally hear it used now in the sense of revealing damaging business or professional secrets – that is, to tell tales out of work.