Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps


Article: a  u or 'ey
  1. Indefinite article, "an" is used before a vowel sound, "a" otherwise
    - an
Noun: a  u or 'ey
  1. The 1st letter of the Roman alphabet
    - A
Noun: Å
  1. The basic unit of electric current adopted under the Système International d'Unités
    "a typical household circuit carries 15 to 50 Ås";
    - ampere, amp
Noun: A  'ey
  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
    - angstrom, angstrom unit
     
  2. The blood group whose red cells carry the A antigen
    - type A, group A
     
  3. (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
    - adenine
     
  4. One of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
    - deoxyadenosine monophosphate
     
  5. Any of several fat-soluble vitamins essential for normal vision; prevents night blindness, inflammation or dryness of the eyes
    - vitamin A, antiophthalmic factor, axerophthol

Derived forms: As

Type of: alphabetic character, base, blood group, blood type, current unit, fat-soluble vitamin, letter, letter of the alphabet, metric linear unit, nucleotide, purine

Part of: abamp, abampere, deoxyribonucleic acid, desoxyribonucleic acid, DNA, Latin alphabet, micromillimeter [US], micromillimetre [Brit, Cdn], millimicron, nanometer [US], nanometre [Brit, Cdn], nm, ribonucleic acid, RNA, Roman alphabet

Encyclopedia: A, B and C