a
a /eɪ/
article
-
(
)
"A" is an indefinite article in English, used before singular nouns that are unspecified or not yet known to the listener. "An" is used before a vowel sound, "a" otherwise
(
a
, an
)
"A" is an indefinite article in English, used before singular nouns that are unspecified or not yet known to the listener. "An" is used before a vowel sound, "a" otherwise
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
(
angstrom
, angstrom unit
, A
)
a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation
Light has a wavelength in the range of 400–700 nm.
Light has a wavelength in the range of 400–700 nm.
-
The blood group whose red cells carry the A antigen
(
A
, group A
, type A
)
the blood group whose red cells carry the A antigen
-
The 1st letter of the Roman alphabet
(
A
)
the 1st letter of the Roman alphabet
-
The basic unit of electric current adopted under the Système International d'Unités
(
A
, ampere
, amp
)
the basic unit of electric current adopted under the Système International d'Unités
A typical household circuit carries 15 to 50 amps
a typical household circuit carries 15 to 50 amps
-
(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
(
A
, adenine
)
(biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA
-
One of the four nucleotides used in building DNA, also known as deoxyadenylate, or dAMP; all four nucleotides have a common phosphate group and a sugar (ribose)
(
A
, deoxyadenosine monophosphate
)
one of the four nucleotides used in building DNA, also known as deoxyadenylate, or dAMP; all four nucleotides have a common phosphate group and a sugar (ribose)
-
Any of several fat-soluble vitamins essential for normal vision; prevents night blindness, inflammation or dryness of the eyes
(
A
, antiophthalmic factor
, axerophthol
, vitamin A
)
any of several fat-soluble vitamins essential for normal vision; prevents night blindness, inflammation or dryness of the eyes
