dyad
\ DAHY-ad \
noun;
1.a group of two; couple; pair.
2.Biology . a. a secondary morphological unit, consisting of two monads: a chromosome dyad. b. the double chromosomes resulting from the separation of the four chromatids of a tetrad.
3.Chemistry . an element, atom, or group having a valence of two. Compare monad, triad (def. 2a).
4.Mathematics . two vectors with no symbol connecting them, usually considered as an operator.
5.Sociology . a. two persons involved in an ongoing relationship or interaction. b. the relationship or interaction itself.
adjective:
1.of two parts; dyadic.
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Quotes:
The novel burrows into the separate and often separated perspectives of this strange dyad , Dial and Che.
-- James Wood, "Notes from Underground," "The New Yorker" , March 3, 2008
...she stayed close by imitating his distance from her with an equal and identical distance from him and, extending out into the world beyond the father-daughter dyad , from all of humanity.
-- Matthew Sharpe, "The Sleeping Father" , 2003
Origin:
Dyad is derived from the Greek word dyad- which meant "pair, equivalent."
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