Keep it under your hat is an interesting idiom that has a somewhat convoluted origin. We will examine the meaning of the phrase keep it under your hat, where it most probably came from and some examples of its use in sentences. Keep it under your hat is an admonishment to keep something secret. Over the years, the idiom
keep it under your hat seems to have undergone a slight shift in meaning. In the mid-1800s the term was used in Britain as an admonishment to keep something in your head, to leave something in your imagination and not bring it to fruition. The oldest example of this use of the phrase is in The History of Pendennis by William Makepeace Thackeray, published in 1848. The idiom traveled to America and underwent a shift in meaning by the 1890s to its current definition, to keep
something secret. There are some who believe that this shift in meaning might be attributable to Abraham Lincoln’s habit of secreting important papers inside the lining of his stovepipe hat. In fact, Lincoln often referred to his hat as his office. There is an origin story that states that keep it under your hat dates back to a time when archers kept their bowstrings under their hats in order to keep them dry. While this is true, the first examples of the idiom keep it under your
hat are not found until centuries later. Examples He says: ‘Keep it under your hat but I’ve got a horse you might like to look at for the Derby’.” (The Telegraph) So if greasy pastries don’t take your fancy, keep it under your hat as you don’t want to anger a hungry Geordie. (The Shields Gazette)
Learn to keep it under your hat until the appropriate time, and all will be well. (The Business Insider)
Keep it under your hat
What's the meaning of the phrase 'Keep it under your hat'?
Keep it secret.
What's the origin of the phrase 'Keep it under your hat'?
On first hearing this seems a rather strange phrase. Why should people put anything under their hats and, even if they were to, why would that be associated with secrecy? The speculation is that putting an item under one's hat would be a way of hiding it. Such trickery is recorded, as in the collection of stories published as The Adventurer, 1793:
"By a sudden stroke of conjuration, a great quantity of gold might be conveyed under his hat."
Let's just get that bowstring under the hat tale out of the way:
- Firstly, keeping dry isn't keeping secret, so even if archers did store strings under their hats, and there's no evidence that they did, where is the connection to the phrase's meaning?
- Secondly, and it would have been kinder to put this first as it entirely dismisses the archer tale, the phrase isn't known in English until the 19th century - so much for a medieval origin.
What else, apart from gold and string, might one keep under one's hat? One's head, of course. The phrase didn't derive from putting anything under one's hat at all - 'under your hat' simply meant 'in your head'. That's the meaning alluded to in early citations of the phrase in print. The oldest of such that I can find is in the novel The History of Pendennis by William Makepeace Thackeray, 1848:
Thus, oh friendly readers, we see how every man in the world has his own private griefs and business... You and your wife have pressed the same pillow for forty years and fancy yourselves united. Psha, does she cry out when you have the gout, or do you lie awake when she has the toothache? ... Ah, sir - a distinct universe walks about under your hat and under mine.
The extended phrase 'keep it under your hat', which didn't arise until the 20th century, simply meant 'keep it in your head', that is, 'think it, but don't say it'. An early example is found in P. G. Wodehouse's Inimitable Jeeves, 1923:
It made such a hit with her when she found that I loved her for herself alone, despite her humble station, that she kept it under her hat. She meant to spring it on me later.