D

Multiple Entries:
  D    d    'd    deuterium  

Concise Oxford English Dictionary © 2008 Oxford University Press:
D1 (also d)

▶noun (pl. 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 CIƆ, an earlier form of M (= 1,000).]

Concise Oxford English Dictionary © 2008 Oxford University Press:
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.

Concise Oxford English Dictionary © 2008 Oxford University Press:
d/diː/

▶abbreviation

• 1 (in genealogies) daughter.

• 2 day(s).

• 3 deci-.

• 4 (in travel timetables) departs.

• 5 (d.) died (used to indicate a date of death).

• 6 Brit. penny or pence (of pre-decimal currency). [from L. denarius ‘penny’.]

• 7 Chemistry denoting electrons and orbitals possessing two units of angular momentum. [d from diffuse, orig. applied to lines in atomic spectra.]

▶symbol

• 1 Mathematics diameter.

• 2 Mathematics denoting a small increment in a given variable.

Concise Oxford English Dictionary © 2008 Oxford University Press:
'd/d/

▶contraction

• 1 had.

• 2 would.

Concise Oxford English Dictionary © 2008 Oxford University Press:
deuterium /djuːˈtɪərɪəm/

▶noun Chemistry a stable isotope of hydrogen with a mass approximately twice that of the usual isotope. (Symbol: D)

– origin 1930s: mod. L., from Gk deuteros ‘second’.