English dictionary
a meaning and definition
Definition and meaning of a at MeaningMonkey.org. a meaning and definition in the English Dictionary.A noun
Definition of A (noun)
- 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: angstrom, angstrom unit
- any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
- synonyms: antiophthalmic factor, axerophthol, vitamin A
- one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
- synonyms: deoxyadenosine monophosphate
- (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
- synonyms: adenine
- the basic unit of electric current adopted under the Systeme International d'Unites
- the 1st letter of the Roman alphabet
- the 1st letter of the Roman alphabet
- the blood group whose red cells carry the A antigen
Source: Princeton University Wordnet