Non sequitur (literary device)

A non sequitur (English pronunciation: /ˌnɒnˈsɛkwᵻtər/; Classical Latin: [noːn ˈsɛkᶣɪtʊr] "it does not follow") is a conversational and literary device, often used for comedic purposes. It is something said that, because of its apparent lack of meaning relative to what preceded it, seems absurd to the point of being humorous or confusing.

This use of the term is distinct from the non sequitur in logic, where it is a fallacy.

Literally, the expression is Latin for "it does not follow." It comes from the words "non" meaning not, and the deponent verb sequor, sequi, secutus sum meaning 'to follow', thus producing sequence and second. (Deponent verbs have passive forms but active meanings.)

A non sequitur can denote an abrupt, illogical, unexpected or absurd turn of plot or dialogue not normally associated with or appropriate to that preceding it. A non sequitur joke has no explanation, but it reflects the idiosyncrasies, mental frames and alternative world of the particular comic persona.

The non sequitur can be understood as the converse of cliché. Examples of non sequiturs are many. Traditional comedy and drama can depend on the ritualization and predictability of human emotional experiences, where the Theatre of the Absurd uses disjunction and unpredictability. The use of non sequitur in humor can be deliberate or unintentional.

...
Wikipedia