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.
Use "duad" in a sentence
"From the monad proceeds an indefinite duad, which is subordinate to the monad as to its cause."
"Pythagorean system, to denote respectively the _monad_, or active principle of nature; the _duad_, or passive principle; the _triad_, or world emanating from their union; and the _quaterniad_, or intellectual science; the whole number of points amounting to ten, the symbol of perfection and consummation."
"A figure used by Pythagoras, consisting of ten points, arranged in a triangular form so as to represent the monad, duad, triad, and quarterniad."