Definitions for A
ə; when stressed eɪA

Princeton's WordNet(2.83 / 26 votes)Rate this definition:

1. A, type A, group A(noun)

   the blood group whose red cells carry the A antigen

2. A, a(noun)

   the 1st letter of the Roman alphabet

3. ampere, amp, A(noun)

   the basic unit of electric current adopted under the Systeme International d'Unites

   "a typical household circuit carries 15 to 50 amps"

4. angstrom, angstrom unit, 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

5. adenine, A(noun)

   (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA

6. deoxyadenosine monophosphate, A(noun)

   one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)

7. vitamin A, antiophthalmic factor, axerophthol, A(noun)

   any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes

Wiktionary(3.64 / 11 votes)Rate this definition:

1. a(Pronoun)

   Alternate form of a.

2. A(Noun)

   An academic grade issued by certain educational institutions. Slightly better than an A.

   I give this novel an A+.

3. A(Noun)

   The highest possible rating.

   I give this novel an A+.

4. A(Noun)

   An academic grade. Where it is used, it is often the best class of result.

   I give this novel an A+.

5. A(Noun)

   A best-first graph search algorithm for finding a lowest cost path to a goal.

6. a(Adverb)

   Alternate spelling of a

7. a(Adjective)

   Alternate spelling of a

Wikipedia(3.50 / 4 votes)Rate this definition:

1. A

   A (named, plural As, A's, as, a's or aes) is the first letter and the first vowel of the modern English alphabet and the ISO basic Latin alphabet. It is similar to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, "a", and its variant "an", is an indefinite article.

Webster Dictionary(4.80 / 5 votes)Rate this definition:

1. A

   the first letter of the English and of many other alphabets. The capital A of the alphabets of Middle and Western Europe, as also the small letter (a), besides the forms in Italic, black letter, etc., are all descended from the old Latin A, which was borrowed from the Greek Alpha, of the same form; and this was made from the first letter (/) of the Phoenician alphabet, the equivalent of the Hebrew Aleph, and itself from the Egyptian origin. The Aleph was a consonant letter, with a guttural breath sound that was not an element of Greek articulation; and the Greeks took it to represent their vowel Alpha with the a sound, the Phoenician alphabet having no vowel symbols

   Etymology: [Shortened form of an. AS. n one. See One.]

2. A

   the name of the sixth tone in the model major scale (that in C), or the first tone of the minor scale, which is named after it the scale in A minor. The second string of the violin is tuned to the A in the treble staff. -- A sharp (A/) is the name of a musical tone intermediate between A and B. -- A flat (A/) is the name of a tone intermediate between A and G

   Etymology: [Shortened form of an. AS. n one. See One.]

3. A

   an adjective, commonly called the indefinite article, and signifying one or any, but less emphatically

   Etymology: [Shortened form of an. AS. n one. See One.]

4. A

   in each; to or for each; as, "twenty leagues a day", "a hundred pounds a year", "a dollar a yard", etc

   Etymology: [Shortened form of an. AS. n one. See One.]

5. A

   in; on; at; by

   Etymology: [Shortened form of an. AS. n one. See One.]

6. A

   in process of; in the act of; into; to; -- used with verbal substantives in -ing which begin with a consonant. This is a shortened form of the preposition an (which was used before the vowel sound); as in a hunting, a building, a begging

   Etymology: [Shortened form of an. AS. n one. See One.]

7. A

   of

   Etymology: [Shortened form of an. AS. n one. See One.]

8. A

   a barbarous corruption of have, of he, and sometimes of it and of they

   Etymology: [Shortened form of an. AS. n one. See One.]

9. A

   an expletive, void of sense, to fill up the meter

   Etymology: [Shortened form of an. AS. n one. See One.]

Freebase(2.50 / 2 votes)Rate this definition:

1. A

   A is the first letter and vowel in the ISO basic Latin alphabet. It is similar to the Ancient Greek letter alpha, from which it derives.

Chambers 20th Century Dictionary(5.00 / 1 vote)Rate this definition:

1. A

   ä or ā, a prep., derived from the old prep.on, and still used, as a prefix, in afoot, afield, apart, asleep, nowadays, twice-a-day; also with verbal nouns, as a-building, to be a-doing, to set a-going. It is now admitted only colloquially. [Short for A.S. an, a dialectic form of on, on, in, at. See Prefixes.]

2. A

   ä, a dialectic corruption of he or she, as in quotha, (Shak.) 'A babbled of green fields.'—A, usually written a', Scotch for all; A, a form of the L. prep. ab, from, of, used before consonants, as in Thomas à Kempis, Thomas à Becket, &c.

Dictionary of Nautical Terms(4.00 / 1 vote)Rate this definition:

1. a

   The highest class of the excellence of merchant ships on Lloyd's books, subdivided into A 1 and A 2, after which they descend by the vowels: A 1 being the very best of the first class. Formerly a river-built (Thames) ship took the first rate for 12 years, a Bristol one for 11, and those of the northern ports 10. Some of the out-port built ships keep their rating 6 to 8 years, and inferior ones only 4. But improvements in ship-building, and the large introduction of iron, are now claiming longer life. A is an Anglo-Saxonism for in or on; as a'board, a'going, &c.

Rap Dictionary(0.00 / 0 votes)Rate this definition:

1. a(verb)

   Going to. And I'm a continue to put the rap down, put the mack down -- Dr. Dre featuring Snoop Doggy Dogg (Nuthin' But a 'G' Thang)

2. a(noun)

   See A-Town.

Editors Contribution(0.00 / 0 votes)Rate this definition:

1. a

   Symbol or letter.

   The letter " a " is used frequently within a unit of grammar.

   Submitted by MaryC on March 25, 2020  

Suggested Resources(3.00 / 1 vote)Rate this definition:

1. a

   Song lyrics by a -- Explore a large variety of song lyrics performed by a on the Lyrics.com website.

Entomology(0.00 / 0 votes)Rate this definition:

1. A

   prefix, is privative; wanting or without.

British National Corpus

1. Spoken Corpus Frequency

   Rank popularity for the word 'A' in Spoken Corpus Frequency: #4

2. Written Corpus Frequency

   Rank popularity for the word 'A' in Written Corpus Frequency: #6

How to pronounce A?

1. Alex

   US English

   Daniel

   British

   Karen

   Australian

   Veena

   Indian

How to say A in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of A in Chaldean Numerology is: 1

2. Pythagorean Numerology

   The numerical value of A in Pythagorean Numerology is: 1

Images & Illustrations of A

Popularity rank by frequency of use