(n.) in rhetoric, a figure of speech in which something is described in terms not directly connected to it
“There’re only four more sleeps til Christmas!” is an example of a figurative rhetorical device and literary technique known as metalepsis.
Also known as transumption, in metalepsis something not immediately connected to something else is nevertheless used to describe it, or else some quality or attribute of it. Think of it as the Kevin Bacon of rhetoric (which is itself, somewhat ironically, a metaleptic statement).
So in the example “four more sleeps til Christmas”, the word sleep is here taken to mean a single night—or rather, a full day and night of 24 hours. This is then used to count down the period remaining until Christmas Day. It is that disconnect, between the words or image being employed and the actual thing being described or referred to, that characterizes metalepsis.
It is the same technique used when people evocatively count down the passing or remaining years in “summers” or “winters”, or even more remotely, in yearly events like “harvests”, “blossoms” or indeed “Christmases.” The extra leap of imagination that metalepses like these force you make in order to understand what someone is actually implying makes metaleptic statements a popular technique among writers, and imagery like this is often encountered in literature and poetry.
This being rhetoric, of course, there’s more to metalepsis than meets the eye. Although in general terms metalepsis involves the describing of something through a more distant element of it, it’s sometimes given a stricter definition—like this, from the Oxford English Dictionary:
The rhetorical figure consisting in the metonymical substitution of one word for another which is itself a metonym.
Clearly, there’s a lot going on here. So let’s explain the explanation.
Metonymy is another figure of speech in which an attribute or something associated with something is used in place of that thing itself. So if x is associated y, using x to refer to y itself is metonymy. If x is an actual constituent part of y, however, we’re dealing with something different again: that is synecdoche.
So when a journalist says that “there has been a statement from the White House”, or “from 10 Downing Street” or “Buckingham Palace,” they’re using metonymy: those buildings are merely associated with the people and institutions that have released the statement (the president, the prime minister and the monarch, respectively). But when someone says they have “two hungry mouths to feed”, they’re using synedoche—because a mouth is an actual part of the thing they’re actually referring to (in this instance, their two children).
What the OED’s definition implies, then, is that in a metalepsis is an extension of metonymy, in which a metonym is used to stand for a metonym, which is itself standing for a metonym. In other words, x is being used to refer to y, which itself being used to describe some attribute of z.
So in the “four more sleeps til Christmas” example, a sleep (x) is something associated with the passing of a 24 hour period (y), and it’s those y’s that are being used to enumerate the time left until Christmas Day (z).
This very strict definition of metalepsis is often only encountered in the highest levels of rhetorical and literary analysis. In more general terms, though, metalepsis simply refers to any figurative description of something that relies on multiple levels or degrees of separation in order to be understood. For that reason, it derives from Greek roots literally meaning ‘higher’ or ‘beyond’ (the source of the prefix meta–) and ‘take’: a metaleptic statement is one that takes its description one or more steps further than a more obvious one.