| 释义 |
duad|ˈdjuːæd|
Also 8 duade.
[ad. Gr. δυάς, δυαδ-, ‘the number two’; prob. influenced by L. duo; the normal repr. of the Gr. is dyad.]
1. A group or combination of two; a couple, a pair.
1660Stanley Hist. Philos. ix. (1701) 378/2 The Duad is indeterminate; Monad is taken according to equality and measure, Duad according to excess and defect. 1751Harris Hermes ii. i. (1786) 226 Δυὰς ἐγνωσµένη, a known Duad, as Apollonius expresses himself. 1793Beddoes Math. Evid. 133 Lord Monboddo..reduces without hesitation, the Greek primitives to the five duads already quoted. 1797Monthly Mag. III. 517 What the Pythagoreans intended to signify by monad, duad, and triad. 1848G. A. Poole Eccl. Archit. Contents x, Three Duads of Ecclesiastical Builders. 1857De Quincey Judas Isc. VII. 32 note, [Aaron] is blind; [Moses] is dumb. But, moving as a co-operating Duad, they become the salvation of Israel.
2. Math. A combination of two things; a pair (considered without reference to the order of the two elements: e.g. ab and ba are the same duad).
Hence duˈadic a., relating to or consisting of duads.
1879Sylvester in Amer. Jrnl. Math. II. 94 Duadic disyntheme, any combination of duads..in which each element occurs twice and no oftener. |