/ɪnˈkrɛdɪbəl/
[adjective] Used to describe something so surprising, impressive, or extreme that it is very hard to believe. In everyday speech, it also simply means something is very good or amazing.
'Incredible' literally means 'not believable' — yet today we use it most often for things we absolutely do believe and love.
The story of 'incredible' begins in ancient Rome, with the Latin verb credere, meaning 'to believe' or 'to trust.' This root was deeply embedded in Roman life — it gave rise to creditum, the idea of trusting someone with money or a promise, and credo, a personal statement of belief. From credere came the adjective credibilis, meaning 'worthy of belief' or 'believable.' When Roman writers wanted to describe something beyond belief, they simply added the prefix in-, which in Latin acts as a negative marker, much like 'un-' in English. The result was incredibilis: literally, 'not believable.'
The word passed from classical Latin into the learned vocabulary of medieval Europe, where scholars and churchmen wrote in Latin and used incredibilis to describe miracles, divine mysteries, and things that strained the limits of human understanding. It was a serious, weighty word — something described as incredibilis was not just surprising, it was genuinely beyond the scope of ordinary reason or experience.
English speakers adopted the word in the 15th century, borrowing it directly from Latin as 'incredible.' At this stage in English history, many educated people read and wrote in Latin, and importing Latin words wholesale was entirely normal. Early uses of 'incredible' in English carried the full weight of its Latin meaning: something incredible was something you genuinely could not or should not believe. Writers used it for tall tales, for miracles, and for reports from distant lands that seemed too strange to be true.
Over the following centuries, 'incredible' began a gradual but significant drift in meaning. By the 17th and 18th centuries, writers were using it not just for things that defied belief but for things that merely astonished or deeply impressed. This process — where a word meaning 'impossible to believe' softens into 'very surprising' and then into 'very impressive' — is extremely common in language history. Words of strong negation often lose their sharp edge over time as speakers reach for them again and again to express enthusiasm.
By the 20th century, this drift had gone even further. 'Incredible' became one of the most popular words in everyday English for expressing admiration or excitement — 'That was incredible!' can now mean simply 'That was wonderful!' with no real question of belief at all. The word has essentially become a general intensifier, a companion to words like 'amazing' and 'fantastic,' which have undergone similar journeys. Linguists call this process 'semantic bleaching' — the original sharp meaning fades like colour from fabric, leaving something softer and more broadly useful.
The Latin root credere left behind a remarkable family of English words, each carrying a thread of the original idea of belief and trust. Latin credere gave us Old French croire and the noun crédit, which became English 'credit.' Latin credo (meaning 'I believe') was borrowed directly into English as 'creed.' Latin credulus (meaning 'too ready to believe') passed into English as 'credulous.' The related Latin noun credentia (meaning 'belief' or 'trust') passed through medieval Latin into Italian credenziale and then into English as 'credentials.' Even the word 'grant' traces back through Old French granter to Latin credere via the idea of trusting someone with something. 'Incredible' stands as perhaps the most dramatic member of this family — the one that took the idea of belief and turned it completely upside down.