/ˈdɪdʒɪt/
[noun] A single number from 0 to 9, or a finger or toe on a human or animal body. The word can refer to something you count on your hands or to a single figure in a number.
Every time you type a PIN number, you are literally using your fingers — because 'digit' originally meant finger.
The story of 'digit' begins with the human hand. The Latin word 'digitus' meant simply 'finger' or 'toe', and it was rooted in the physical, everyday act of pointing and counting. Romans used their fingers to tally things — markets, debts, harvests — and so the finger became inseparable from the concept of counting itself. The word entered Middle English in the 14th century directly from Latin 'digitus', initially keeping its bodily meaning intact.
The leap from finger to number happened naturally, because counting on fingers is one of humanity's oldest and most universal habits. Roman mathematicians began using 'digitus' to refer to the numbers one through nine — the quantities a person could represent on their fingers alone. This is also why we use a base-10 number system: most humans have ten fingers, and we have been counting on them since before written history. The number zero was a later philosophical and mathematical addition, eventually folded into the digit family.
The word travelled through Medieval Latin scholarly texts into early English scientific writing, where it described single figures in arithmetic. By the 15th and 16th centuries, writers and scholars in England were using 'digit' to mean any numeral from 0 to 9, especially in the context of mathematics and astronomy. The astronomical connection is interesting — medieval astronomers measured angles and celestial distances in units called digits, equal roughly to the width of a finger held at arm's length.
The Latin root 'digitus' has been extraordinarily productive in English. Through Latin 'digitus' came 'digital', originally meaning 'of or relating to fingers', which took on its modern electronic meaning only in the 20th century when engineers described binary signals — sequences of 0s and 1s — as 'digital' because they worked in discrete number steps. Also from the same Latin root came 'dexterity' via a slightly different path: Latin 'dexter' (meaning right-handed, skilled) shares a deep Proto-Indo-European ancestor with 'digitus', pointing back to an ancient root connected to the idea of pointing or directing. More directly, Latin 'digitus' → Old French 'doigt' → modern French 'doigt' (finger), while in English the Latin form was borrowed directly without passing through French.
Perhaps the most remarkable thing about 'digit' is how it bridges the physical and the abstract without losing either meaning. We still use it in medicine and biology to describe fingers and toes — a 'digitigrade' animal, like a cat or dog, walks on its digits. And we use it in mathematics, computing, and everyday life to mean a single numeral. The word quietly reminds us that numbers and bodies are not separate things — that human mathematics grew quite literally from the ends of our hands, and that every PIN code, every phone number, every price tag is, in a small and beautiful way, a row of fingers.