D 1
(also d )
■ noun ( plural Ds or D's )
1》 the fourth letter of the alphabet.
2》 denoting the fourth in a set of items, categories, sizes, etc.
3》 Music the second note of the diatonic scale of C major.
4》 the Roman numeral for 500. [understood as half of CI, an earlier form of M (= 1,000).]
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D 2
■ abbreviation
1》 (in the US) Democrat or Democratic.
2》 depth (in the sense of the dimension of an object from front to back).
3》 Chemistry dextrorotatory.
4》 (with a numeral) dimension(s) or dimensional.
5》 (in tables of sports results) drawn.
6》 Germany (international vehicle registration). [from Ger. Deutschland .]
■ symbol
1》 Physics electric flux density.
2》 Chemistry the hydrogen isotope deuterium.