/hɑːf/
[noun] One of two equal parts that something is divided into. It can also be used as an adjective or adverb to mean 'partly' or 'not fully', as in 'half asleep' or 'half a loaf of bread'.
The word 'half' originally meant 'side' or 'flank' — not a fraction at all, but a physical part of something cut away.
The word 'half' reaches back to the earliest layers of the English language, appearing in Old English as 'healf', a word that carried a meaning slightly different from what we use today. In its oldest sense, 'healf' did not simply mean one of two equal portions — it meant 'side' or 'flank', as in the side of a body or the flank of an animal. The mathematical idea of an exact fifty-percent division grew from this more physical, spatial root. You can still feel that original sense in phrases like 'on behalf of', where 'behalf' comes from Old English 'be healfe', meaning 'by the side of' someone.
The Old English 'healf' is descended from the Proto-Germanic root '*halba-', which also gave rise to related words in other early Germanic languages. Old High German contributed 'halb', Old Norse offered 'halfr', Gothic had 'halbs', and Old Saxon used 'half'. All of these point back to the same ancestral form, which linguists trace to a Proto-Indo-European root '*skel-' or '*kel-', meaning 'to cut' or 'to divide'. So at its very deepest origin, 'half' carries the idea of something cut apart — a fitting ancestor for a word about division.
When the Vikings settled in Britain during the 8th and 9th centuries, their Old Norse word 'halfr' would have sounded very familiar to Anglo-Saxon speakers, reinforcing rather than replacing the native English word. This kind of mutual reinforcement was common between Old English and Old Norse, two closely related Germanic languages that overlapped significantly in vocabulary. The result was that 'half' survived and thrived through the tumultuous linguistic shifts of the early medieval period, even as French flooded into English after the Norman Conquest of 1066.
Norman French did introduce some competing words for division — 'demi' (from Latin 'dimidius') and 'semi' (from Latin 'semi-') — and both of these are still visible in English today in words like 'demitasse' and 'semicircle'. But unlike many Old English words that were pushed aside or reduced in status by French equivalents, 'half' held its ground entirely. It was too embedded in everyday speech to be displaced. Its simplicity — a single syllable, easy to pronounce in any context — gave it tremendous staying power.
Over the centuries, 'half' grew into a remarkably productive word, generating dozens of compound words and fixed expressions. 'Halfway', 'halfhearted', 'half-time', 'half-baked', and 'better half' all extend the core idea in different directions. The phrase 'not half' became a British English intensifier meaning 'very much indeed', while 'half-hearted' perfectly captured the idea of doing something without full commitment. Perhaps most interestingly, 'half' found its way into units of currency — the 'halfpenny' was a real coin in British money for centuries, finally withdrawn from circulation in 1984, making 'half' a word that literally shaped economic life.
What is most striking about 'half' is just how little it has changed over more than a thousand years. The Old English 'healf' and the modern 'half' are almost identical in form and nearly identical in meaning. In a language that has transformed almost beyond recognition since the days of Beowulf, 'half' stands as a quiet monument to continuity — a reminder that the most useful, most everyday words are often the ones that time leaves almost completely untouched.