An anacoluthon (/ænəkəˈljuːθɒn/; from the Greek anakolouthon, from an- 'not', and akólouthos 'following') is an unexpected discontinuity in the expression of ideas within a sentence, leading to a form of words in which there is logical or grammatical incoherence of thought.
Anacolutha are very common in informal speech, where a speaker might start to say one thing, then break off and abruptly and incoherently continue, expressing a completely different line of thought.
The word anacoluthon is a transliteration of the Greek ἀνακόλουθον (anakólouthon), which derives from the privative prefix ἀν- an- 'not', and the root adjective ἀκόλουθος akólouthos 'following'.
The anacoluthon is a failure to follow on, an unconscious departure from the grammatical scheme with which a sentence was started, the getting switched off, imperceptibly to the writer, very noticeably to his readers, from one syntax track to another.The word, though not the underlying meaning (see malapropism), has been somewhat popularized due to its use as an expletive by Captain Haddock in the English translations of The Adventures of Tintin series of children's books.
She argues that it involves "the employing of multiple discursive ranges and disjunctive transpositions from one to the other[,] hence in any one poem, far from being in one mode, one register, one stable voice, a writer is like an acrobat ... a Barthesean weaver of a wacky fabric, or someone who 'samples', like a certain kind of contemporary DJ".