A — English Dictionary

Character

1. The first letter of the English alphabet, called a and written in the Latin script.

   Usage

   • letter
   • uppercase

   Related words

   A-frameABCA.B.C.A to ZA wave

   Examples

   Apple starts with A.

   Boxer could not get beyond the letter D. He would trace out A, B, C, D, in the dust with his great hoof […]

Numeral

1. The first numeral symbol of the English alphabet, called a and written in the Latin script.

   Usage

   • uppercase
   • number

   Examples

   Item A is "foods", item B is "drinks".

1. A rank, normally the highest rank, on any of various scales that assign letters.

   Examples

   We assign each item inspected a rating from A through G, depending on various factors.

   In the UK, the highest social grade is A – upper middle class.

   More examples (1)

   The only standard brassiere cup size smaller than the A cup is the AA cup.

2. The highest letter grade assigned (disregarding plusses and minuses).

   Examples

   I was so happy to get an A on that test.

   Darcy's pretty sharp. She pulls A's.

3. A tone three fifths above C in the cycle of fifths; the sixth tone of the C major scale; the first note of the minor scale of A minor; the reference tone that occurs at exactly 440 Hz; the printed or written note A; the scale with A as its keynote.

   Examples

   Orchestras traditionally tune to a concert A.

4. A blood type that has a specific antigen that aggravates the immune response in people with type B antigen in their blood. People with this blood type may receive blood from type A or type O but cannot receive blood from AB or B.

   Examples

   My blood type is A negative.

5. Mass number.

6. A universal affirmative suggestion.

7. Allele dominant.

Noun

1. Ace. (including in card games)

2. Acre.

3. Adult; as used in film rating.

4. Ammeter.

5. Angstrom.

   Usage

   • nonstandard

6. Answer.

7. An assist.

8. Asexual.

9. Arsehole.

   Usage

   • London
   • UK usage

10. Atom.

    Examples

    A-bomb

Adjective

1. Atom; atomic.

Noun

1. a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation

   Synonyms

   angstromangstrom unit

   Broader terms

   metric linear unit

2. any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes

   Synonyms

   vitamin Aantiophthalmic factoraxerophthol

   Broader terms

   fat-soluble vitamin

3. nucleotide derived from adenine with a deoxyribose sugar and a phosphate group

   Synonyms

   deoxyadenosine monophosphatedAMPdeoxyadenylic aciddeoxyadenylate

   Broader terms

   nucleotidebase

4. (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA

   Synonyms

   adenine

   Broader terms

   purine

5. the basic unit of electric current adopted under the Systeme International d'Unites

   Synonyms

   ampereamp

   Broader terms

   current unit

   Examples

   a typical household circuit carries 15 to 50 amps

6. the 1st letter of the Roman alphabet

   Synonyms

   a

   Broader terms

   letterletter of the alphabetalphabetic character

7. the blood group whose red cells carry the A antigen

   Synonyms

   type Agroup A

   Broader terms

   blood groupblood type