/wiːk/
[noun] A period of seven days, usually starting on Monday or Sunday. It is one of the basic units of time that people use to organise their work, rest, and daily life.
The seven-day week was invented in ancient Mesopotamia and named after celestial bodies — so every day you say 'Tuesday', you are honouring the Norse god of war.
The word 'week' comes from Old English 'wice' or 'wucu', which meant a cycle or a turning — suggesting early speakers thought of the week not as a straight line of days but as something that rotated and came back around. This Old English word descended from Proto-Germanic '*wikō', which carried the sense of a sequence or a series. Related forms appear across the Germanic family of languages: Old High German 'wehha', Old Norse 'vika', Dutch 'week', and Gothic 'wikō' all share this common ancestor, pointing to a concept that was deeply embedded in Germanic culture long before any of these languages were written down.
The seven-day week itself is far older than the English word for it. It was developed in ancient Mesopotamia — in what is now Iraq — by the Babylonians, who were skilled astronomers and who associated each day with one of the seven celestial bodies they could observe with the naked eye: the Sun, the Moon, Mars, Mercury, Jupiter, Venus, and Saturn. This system passed into the Hellenistic world and was then adopted enthusiastically by the Romans, who spread it across their vast empire. By the time Germanic tribes encountered the Roman calendar, the seven-day week was already firmly established.
The Romans named their days in Latin after the same seven celestial bodies: dies Solis (day of the Sun), dies Lunae (day of the Moon), dies Martis (day of Mars), dies Mercurii (day of Mercury), dies Jovis (day of Jupiter), dies Veneris (day of Venus), and dies Saturni (day of Saturn). When Germanic-speaking peoples adopted the Roman week, they made a fascinating cultural substitution: they replaced the Roman gods with their own equivalent Norse and Germanic deities, but kept Saturn's day and the Sun and Moon's days largely intact. So dies Martis, named for the Roman god of war Mars, became 'Tiwesdæg' — Tuesday — named for Tiw (or Tyr), the Norse god of war. Dies Mercurii became 'Wōdnesdæg' — Wednesday — after Woden (Odin). Dies Jovis became 'Þūnresdæg' — Thursday — after Þunor, or Thor, god of thunder. Dies Veneris became 'Frīgedæg' — Friday — after Frigg or Freyja, goddess of love.
What is remarkable is how stable this system has proved. The names of the days in English are essentially a patchwork of Roman astronomy, Roman mythology, and Norse religion, all stitched together more than a thousand years ago and carried forward almost unchanged. When you say 'Wednesday', you are speaking a word that Old English speakers used to honour Woden — the chief god of the Anglo-Saxon pantheon — in a linguistic tradition that stretches back to the Germanic tribes of the early centuries CE. Languages closer to Latin, like French and Spanish, kept the Roman gods' names instead: French 'lundi' (Monday) comes directly from Latin 'dies Lunae', and 'vendredi' (Friday) from 'dies Veneris'.
The Proto-Germanic root '*wikō' is thought by some scholars to connect to a root meaning 'to bend' or 'to yield', which would reinforce the idea of a cycle — something that turns and returns. Others link it to the sense of a 'change' or 'sequence of turns', which may reflect the practical reality that different days were designated for different activities: market days, rest days, and working days in early Germanic societies. The Old English 'wice' also gave rise to the word 'wicked' in a roundabout way — though that is a different story — and the phrase 'a week of Sundays', meaning a very long time, shows how deeply the week became embedded in English speakers' sense of duration and rhythm.
By the Middle English period, 'wice' had smoothed into 'weke' and then into the modern 'week', losing its earlier sense of rotation but keeping its core meaning perfectly intact. Today, the word is so ordinary that we rarely pause to consider that contained within it — and within the seven names of its days — is an extraordinary layering of Babylonian science, Roman religion, Norse mythology, and Germanic tribal life, all compressed into a single syllable that we use without a second thought every time we plan our lives seven days at a time.