D1
(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[s]3ZCCGQGCV2_B8D1B6EE.bmp[/s], an earlier form of M (= 1,000).]
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D2
¦ 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.