Siamese twins (linguistics) also known as a trinomial. Another name for this collocation is tricolon when the three parts are of the same or consistent grammatical form. Many of these could be considered triplets and satisfy the rule of three in writing. Siamese twins (linguistics) Siamese twins (also irreversible binomials, binomials, binomial pairs, nonreversible word pairs, or freezes) in the context of the English language refer to a pair or group of words used together as an idiomatic expression or collocation, usually conjoined by the words "and" or "or". The order of elements cannot be reversed. The expressions "milk and honey" (two nouns),
There are known knowns management and strategic planning circles. Known unknowns refers to "risks you are aware of, such as cancelled flights..." Unknown unknowns are risks that come from situations that are so unexpected that they would not be considered. "For example, prior to the invention of the personal computer, manufacturers of typewriters probably didn't foresee the risks to their business". Contemporary usage is largely consistent with the earliest known usages. For example, the term was used in evidence given to the British Columbia Royal Commission of Inquiry into Uranium Mining in 1979: The term also appeared in a 1982 "New Yorker" article on