A (disambiguation) explained
A (disambiguation) should not be confused with Å (disambiguation).
A is the first letter of the Latin and English alphabet.
A may also refer to:
Science and technology
Quantities and units
Astronomy
Biology
- A+ and A−, human blood types
- Vitamin A, also called retinol, an essential human nutrient
- Haplogroup A (mtDNA), a human mitochondrial DNA (mtDNA) haplogroup
- Haplogroup A (Y-DNA), a Y-chromosomal DNA (Y-DNA) haplogroup
- Adenine, a nucleic acid
- Adenosine, a nucleoside
- A (or Ala), abbreviation for amino acid alanine
- ATC code A, Alimentary tract and metabolism, a section of the Anatomical Therapeutic Chemical Classification System
Computing
Programming languages
Other uses in computing
Mathematics and logic
- A numerical digit meaning ten in hexadecimal and other positional numeral systems with a radix of 11 or greater
- Sometimes in blackboard bold represents the algebraic numbers (
) (U+1D538 in Unicode)
, an inverted letter A)
Other uses in science and technology
- A battery, a vacuum tube filament type battery
- A battery (size), a standard battery size
- Anode, an electrode
- A, historical symbol for chemical element argon, currently Ar
- The center of a hexagonal face of the Brillouin zone of a hexagonal lattice, in physics
Arts and media
Books
- "A", a poem by twentieth century author Louis Zukofsky
- a, A Novel, by twentieth century artist Andy Warhol
- A, the name of the Fourth Raikage, the leader of Kumogakure in the Naruto manga series
- A (Pretty Little Liars), the main antagonist in the Pretty Little Liars book and TV series
- A (for "adultery"), the titular letter in the novel The Scarlet Letter
- "A" Is for Alibi, the first novel in Sue Grafton's "Alphabet mystery" series, published in 1982
- Matthew Arnold, who used the pseudonym "A"
- Isaac Asimov, who used the pseudonym "Dr. A"
- Alexander Pope, who used the pseudonym "A"
Film and TV
Films
Film ratings
Television
Music
Performers
- A (band), a British alternative rock band
Albums
- A (Agnetha Fältskog album), 2013
- A (Cass McCombs album), 2003
- A (Jimmy Raney album), 1957
- A (Jethro Tull album), 1980
- A (Usher and Zaytoven album), 2018
- A, a Denki Groove album (read as "Ace")
- A (Ayumi Hamasaki EP), 1999
- A (single album), a 2015 single by the Korean band Big Bang
- A!, Alexa Feser 2019
- A' (album), an album by Afrirampo
Songs
Other media
Geography
- Austria, on the vehicle registration plates of the European Union
- "The A", a nickname for the U.S. city of Atlanta, Georgia
Linguistics
Letters
- A (or a), the first letter of the Latin alphabet
- A (Indic), the many form of brahmic "a"
- A (Bengali), the romanized name of the Bengali letter অ
- A (cuneiform), the romanized name of a cuneiform sign
- A (Cyrillic) (A or а), the first letter of the Cyrillic alphabet
- A (kana) (or a), the romanized name of the Hiragana syllable letter あ and of the Katakana syllable letter ア used in Japanese, which may also be used to represent Asia
- Alpha (Α or α), the first letter of the Greek alphabet
Other uses in linguistics
- A and an, the indefinite article in English
- A, a glossing abbreviation for agent-like argument of canonical transitive verb
- pronounced as /a/, the IPA representation of the open front unrounded vowel
- pronounced as /ɑ/, the IPA representation of the open back unrounded vowel
- a., an abbreviation of ante (Latin for "before") used in etymologies
People
- A (pharaoh), an Egyptian pharaoh
- A Martinez, an American actor and singer
- Matthew Arnold, who used the pseudonym "A"
- Isaac Asimov, who used the pseudonym "Dr. A"
- Alexander Pope, who used the pseudonym "A"
- Brfxxccxxmnpcccclllmmnprxvclmnckssqlbb11116, a Swedish child born in 1991, alternately called "A"
Philosophy and religion
Transport
Automobile
- Ford Model A, a name used by two separate cars produced by the Ford Motor Company:
- Geometry A, an electric mid-size sedan by Geely Auto
Rail
Ships
- A (motor yacht) (M/Y A), a 119m yacht owned by Andrey Melnichenko
- A (sailing yacht) (S/Y A), a 143m yacht owned by Andrey Melnichenko
- , a Kaiserliche Marine tanker
Other uses
- A (grade), an academic grade
- A series of paper sizes defined by ISO 216, e.g. A4, A5 sizes
- A formation, an American football offensive formation
- A-Frame, a type of structure
- Ace, a playing card
- Agilent Technologies, with U.S. ticker symbol A
- Sentinel Peak (Arizona), more commonly known as "A" Mountain for the human-made rock formation in the shape of the letter
- Alfa, the military time zone code for UTC+01:00
- Farmall A, a tractor produced by International Harvester from 1939 to 1947
- Oakland A's, or the Athletics, a professional baseball team based in Oakland, California, United States
See also
