Origins
The word 'change' entered English in the early thirteenth century from Old French 'changier' (to alter, to exchange), which descended from Late Latin 'cambiāre' (to exchange, to barter). The Late Latin word is generally considered to be of Celtic origin, borrowed into Latin during the Roman period from Gaulish or another Continental Celtic language. The likely Celtic root is *kamb-, meaning 'crooked' or 'bent,' preserved in Old Irish 'camm' (crooked) and Welsh 'cam' (crooked, bent). If this etymology is correct, the underlying metaphor of 'change' is one of bending or deviation — a departure from the straight course, a turning aside from what was.
This Celtic-to-Latin borrowing is part of a small but significant group of words that entered Latin from the Celtic languages spoken across Gaul and the Iberian Peninsula. The Romans, while politically dominant, freely borrowed practical commercial vocabulary from the peoples they conquered, and 'cambiāre' appears to have been a marketplace term for bartering and exchanging goods.
From Late Latin, the word passed into all the major Romance languages: French 'changer,' Spanish 'cambiar,' Italian 'cambiare,' Portuguese 'cambiar,' and Romanian 'a schimba.' The international financial term 'cambio' (used for currency exchange offices across Europe and Latin America) preserves the original commercial sense of the word. A 'bureau de change' — a currency exchange office — uses 'change' in its oldest surviving meaning.
Semantic Evolution
In English, 'change' initially carried the primary sense of 'exchange' or 'substitution': to change one thing for another. The sense of 'alteration' — making something different without replacing it — developed as a secondary meaning during the thirteenth and fourteenth centuries. The monetary sense ('change' as the coins returned from a transaction) emerged naturally from the exchange meaning: one gives a large coin and receives the exchange, the smaller coins that make up the difference.
The word 'exchange' itself is a close relative, formed from Old French 'eschangier' (to exchange), with the Latin prefix 'ex-' (out) added to 'changier.' 'Interchange' adds the prefix 'inter-' (between). 'Changeling' — a child secretly substituted for another, especially in folklore by fairies — preserves the original 'substitution' sense in a context of supernatural exchange.
Phonologically, the word underwent the characteristic Anglo-Norman changes that distinguish English borrowings from continental French. The initial 'ch' was pronounced /tʃ/ (as in 'church') in the Anglo-Norman dialect spoken in post-Conquest England, while in Parisian French it evolved to /ʃ/ (as in 'shoe'). This is why English has 'change' with /tʃ/ while modern French has 'changer' with /ʃ/.
Legacy
The word's cultural weight has grown enormously in the modern era. Political movements rally around 'change' as a slogan. Barack Obama's 2008 campaign built its identity around the single word. Philosophical traditions from Heraclitus ('everything changes') to Buddhist impermanence (anicca) have been expressed in English through this word. The concept of change as fundamental to existence is ancient, but the English word for it traces not to an abstract philosophical tradition but to a Celtic root meaning 'crooked' — a reminder that even our most abstract vocabulary often begins in the tangible, the physical, and the commercial.