a
Meanings
- a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
- any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
- one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
- (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
- the basic unit of electric current adopted under the Systeme International d'Unites;
- "a typical household circuit carries 15 to 50 amps"
- the 1st letter of the Roman alphabet
- the blood group whose red cells carry the A antigen
Synonyms
a is not a valid Scrabble word
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