/tʃɪŋk/
[noun] A small, narrow crack or opening in a surface, such as a wall or door, that lets in light or air. The word can also refer to a brief, high-pitched ringing sound, like coins hitting each other.
The word 'chink' for a crack in armour gave the world one of its most famous idioms — the one tiny weakness that brings down the mightiest opponent.
The word 'chink' meaning a narrow crack or fissure traces back to the Old English word 'cine' or 'cinu', which meant a crack, fissure, or cleft in a surface. This Old English root is connected to the Proto-Germanic verb *kinan, meaning 'to burst open' or 'to split apart', a root shared by other Germanic languages. The idea at its heart is elemental and physical — the splitting of something solid, the gap that appears where wholeness once existed.
By the early 15th century, the word had evolved in Middle English into forms like 'chine' and eventually 'chink', with the addition of the final 'k' sound reflecting a common phonetic shift in late medieval English. The word was used practically and concretely — it described the gaps between planks in a wooden ship, the cracks in castle walls, and the spaces between stones in a fortress. For people living in draughty medieval buildings, a chink was not merely a poetic image but a daily, felt reality.
The phrase 'a chink in one's armour' emerged from this very practical world of knights and soldiers. A suit of armour was designed to be seamless protection, but any small gap — at the joint of the elbow, beneath the visor, at the neck — could prove fatal. That tiny opening, that chink, became a powerful metaphor for a hidden weakness in an otherwise strong person or plan. The phrase entered figurative use in English by the 16th and 17th centuries and remains one of the most durable idioms in the language today.
A separate but related sense of 'chink' — meaning a brief, sharp, metallic ringing sound, like coins or glasses touching — developed in the 16th century. This usage is likely imitative or 'echoic' in origin, meaning the word itself sounds like the noise it describes. This is a completely independent thread of meaning from the crack or fissure sense, though both share the same spelling and pronunciation. Over time, 'chink' as a sound became associated particularly with money, giving rise to the informal expression 'the chink of coins'.
It is worth noting that the word also exists as a highly offensive ethnic slur, which developed separately in the 19th century as a derogatory term. This slur is entirely unrelated in etymology to the Old English 'cinu' or the echoic sound word, but it has unfortunately cast a shadow over the older, innocent meanings of the word in some contexts. Etymologists are careful to distinguish these completely separate linguistic histories, as conflating them distorts the true origin of a much older and entirely neutral word.
Today, 'chink' in its original sense remains a vivid and useful word, particularly in literary and descriptive writing. A chink of light slipping through a curtain, a chink in someone's confident façade — these are images that carry real weight precisely because the word is so precise. It does not describe a large gap or a wide opening; it describes something narrow, specific, and revealing. That precision is what has kept the word alive in the language for more than five hundred years.