from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A unit of two objects; a pair.
from The Century Dictionary.
- noun Same as
- noun In mathematics, an unordered, pair; two objects considered as making up one, and as the same one whichever is taken first.
from the GNU version of the Collaborative International Dictionary of English.
- noun rare A union of two; duality.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun A
- noun mathematics an
- noun astrology dwadasama
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun two items of the same kind
from The American Heritage® Dictionary of the English Language, 4th Edition
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.
That from the monad and the indefinite duad proceed numbers.
It is possible to think of the soul as a reincarnating entity, whether it be a monad, duad, triad, or septenary being.
It would be interesting to know why this duad remains as a duad in selenium and breaks up into a septad and triad in the other members of the group.
The contained bodies in the pillars run three, four, five, four, three, two, instead of starting with two; and a quartet replaces a duad in the globes above.
The pillars are the same as in chlorine and its congeners, with a duad added at the base.
Apart from this, the composition is simple enough, all the ovoids being alike, and composed of a triplet, a septet and a duad.
They yield, on the hyper level, two triads, a duad, and a unit.