The ampersand is, quite literally, a word wearing the shape of a letter. It began as the Latin et, meaning and, written so often and so fast that the two letters fused into a single character, a ligature binding e and t together. Look closely at some forms of the mark and you can still see the ghost of both letters caught in the curve. It is one of the oldest such fusions in the alphabet's history, ancient enough to appear in the graffiti scratched onto the walls of Pompeii, which means people were already collapsing and into this shorthand nearly two thousand years ago.

If the shape comes from Latin, the name comes from a schoolroom mishearing. For a long time the character was treated as a sort of honorary letter, recited at the end of the alphabet alongside the true ones. But a symbol standing where a letter stands needs a way to be named without confusion, so children reciting the alphabet ended it with a small Latin formula: and per se and, meaning and, by itself, and, a way of saying that this last mark was the word and standing on its own. Recited daily by generations of pupils, the phrase wore down the way spoken things do. The slurring compressed and per se and into a single run of sound, and that mangled recitation settled into ampersand, the name we still use.

So the character carries a double history in plain sight. Its body is a Roman scribe's convenience, two letters hurried into one. Its name is a mishearing of the sentence children used to explain what it was. Both origins are acts of compression, of language folding in on itself under the pressure of daily use, and the ampersand preserves them both: a word that became a letter, given a name that was once a whole spoken phrase.