Definition of "dyad" [dy•ad]

• Two individuals or units regarded as a pair: the mother-daughter dyad. (noun)
• Biology One pair of homologous chromosomes resulting from the division of a tetrad during meiosis. (noun)
• Chemistry A divalent atom or radical. (noun)
• Mathematics A function that draws a correspondence from any vector u to the vector (v·u)w and is denoted vw, where v and w are a fixed pair of vectors and v·u is the scalar product of v and u. For example, if v = (2,3,1), w = (0,-1,4), and u = (a,b,c), then the dyad vw draws a correspondence from u to (2a + 3b + c)w. (noun)
• Mathematics A tensor formed from a vector in a vector space and a linear functional on that vector space. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "For example, "the dyad" is the term Murray used for the experiment he performed on Kaczynski and other students."
• "The rake/victim dyad is organized around the cultural power that men have and women do not."
• "The more powerful person in a dyad is the one who has the license to touch."