noun, plural A’s or As, a’s or as.
- the first letter of the English alphabet, a vowel.
- any spoken sound represented by the letter A or a, as in bake, hat, father, or small.
- something having the shape of an A.
- a written or printed representation of the letter A or a.
- a device, as a printer’s type, for reproducing the letter A or a.
- from A to Z, from beginning to end; thoroughly; completely: He knows the Bible from A to Z.
- not know from A to B, to know nothing; be ignorant.
- are; ares.
- not any particular or certain one of a class or group: a man; a chemical; a house.
- a certain; a particular: one at a time; two of a kind; A Miss Johnson called.
- another; one typically resembling: a Cicero in eloquence; a Jonah.
- one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (compare hundreds of men); a dozen times (compare dozens of times).
- indefinitely or nonspecifically (used with adjectives expressing number): a great many years; a few stars.
- one (used before a noun expressing quantity): a yard of ribbon; a score of times.
- any; a single: not a one.
- each; every; per: ten cents a sheet; three times a day.
- Pronunciation Spelling. a reduced, unstressed form of of (often written as part of a single, unhyphenated word): cloth a gold; time a day; kinda; sorta.
auxiliary verb Pronunciation Spelling.
- a reduced, unstressed form of auxiliary have following some modals, as might, should, could, would, and must (usually written as part of a single, unhyphenated word): We shoulda gone.
pronoun British Dialect.
- Electricity. ampere; amperes.
- Physics. angstrom.
- British. arterial (used with a road number to designate a major highway): Take the A525 to Ruthin.
- the first in order or in a series.
- (sometimes lowercase)(in some grading systems) a grade or mark, as in school or college, indicating the quality of a student’s work as excellent or superior.
- (sometimes lowercase)(in some school systems) a symbol designating the first semester of a school year.
- the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor.
- a string, key, or pipe tuned to this tone.
- a written or printed note representing this tone.
- (in the fixed system of solmization) the sixth tone of the scale of C major, called la.
- the tonality having A as the tonic note.
- Physiology. a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group A or AB and to receive blood from persons of O or A.Compare ABO system.
- (sometimes lowercase)the medieval Roman numeral for 50 or 500.Compare Roman numerals.
- Chemistry. (formerly) argon.
- Chemistry, Physics. mass number.
- Logic. universal affirmative.
- British. a designation for a motion picture recommended as suitable for adults.Compare AA(def 5), U(def 6), X(def 9).
- a proportional shoe width size, narrower than B and wider than AA.
- a proportional brassiere cup size, smaller than B and larger than AA.
- a quality rating for a corporate or municipal bond, lower than AA and higher than BBB.
- Scot.all: for a’ that.
- a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun in a prepositional phrase, forming a predicate adjective or an adverbial element (afoot; abed; ashore; aside; away), or before an adjective (afar; aloud; alow), as a moribund prefix with a verb (acknowledge), and in archaic and dialectal use before a present participle in -ing (set the bells aringing); and added to a verb stem with the force of a present participle (ablaze; agape; aglow; astride; and originally, awry).
- a reduced form of the Old English preposition of: akin; afresh; anew.
- an old point-action prefix, not referring to an act as a whole, but only to the beginning or end: She arose (rose up). They abided by their beliefs (remained faithful to the end).
- variant of ab- before p and v: aperient; avert.
- variant of ad-, used: (1) before sc, sp, st (ascend) and (2) in words of French derivation (often with the sense of increase, addition): amass.
- variant of an-1 before a consonant, meaning “not,” “without”: amoral; atonal; achromatic.
- atomic (used in combination): A-bomb; A-plant.
- acre; acres.
- ampere; amperes.
- are; ares.
- Baseball. assist; assists.
- a plural ending of nouns borrowed from Greek and Latin: phenomena; criteria; data; errata; genera.
- a feminine singular ending of nouns borrowed from Latin and Greek, also used in Neo-Latin coinages to Latinize bases of any origin, and as a Latin substitute for the feminine ending -ē of Greek words: anabaena; cinchona; pachysandra.
- an ending of personal names forming feminines from masculines: Georgia; Roberta.
- a suffix designating the oxide of the chemical element denoted by the stem: alumina; ceria; thoria.
- the first letter of the Greek alphabet (A, α).
- the vowel sound represented by this letter.
- the first; beginning.
- (initial capital letter)Astronomy. used to designate the brightest star in a constellation.
- Chemistry. one of two or more isomeric compounds.
- the first in a series of related items: frequently used in chemistry and physics.
- Chiefly British. a mark or grade corresponding to an A.Compare beta(def 8), gamma(def 9).
- (of an animal) having the highest rank in a dominance hierarchy: the alpha female of an elephant pack.
- being the most dominant, powerful, or assertive person in a particular group.
See also alpha male.
- alphabetical: Put the files in alpha order.
- Chemistry. pertaining or linked to the carbon atom closest to a particular group in an organic molecule.
- , 1502–72,Italian painter.
noun plural a’s, A’s or As
- the first letter and first vowel of the modern English alphabet
- any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra
- Also called: alphathe first in a series, esp the highest grade or mark, as in an examination
- from A to Zfrom start to finish, thoroughly and in detail
determiner (indefinite article; used before an initial consonant)
- used preceding a singular countable noun, if the noun is not previously specified or knowna dog; a terrible disappointment
- used preceding a proper noun to indicate that a person or thing has some of the qualities of the one nameda Romeo; a Shylock
- used preceding a noun or determiner of quantitya cupful; a dozen eggs; a great many; to read a lot
- used preceding a noun indicating a concrete or abstract thing capable of being dividedhalf a loaf; a quarter of a minute
- (preceded by once, twice, several times, etc) each or every; peronce a day; fifty pence a pound
- a certain; oneto change policy at a stroke; a Mr Jones called
- (preceded by not)any at allnot a hope
- an informal or dialect word for have they’d a said if they’d known
- (usually linked to the preceding noun) an informal form of of sorta sad; a kinda waste
- are(s) (metric measure of land)
- chess See algebraic notation
- a note having a frequency of 440 hertz (A above middle C) or this value multiplied or divided by any power of 2; the sixth note of the scale of C major
- a key, string, or pipe producing this note
- the major or minor key having this note as its tonic
- a human blood type of the ABO group, containing the A antigen
- (in Britain) a major arterial roadthe A3 runs from London to Portsmouth
- (formerly, in Britain)
- a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see
- (as modifier)an A film
- mass number
- the number 10 in hexadecimal notation
- chemargon (now superseded by Ar)
- Also: atampere-turn
- absolute (temperature)
- (in circuit diagrams) ammeter
- (in combination)atomican A-bomb; an A-plant
- logica universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaPCompare E, I 2, O 1
- a person whose job is in top management, or who holds a senior administrative or professional position
- (as modifier)an A worker See also occupation groupings
- Austria (international car registration)
- angstrom unit
- not; without; opposite toatonal; asocial
- on; in; towardsafoot; abed; aground; aback
- literary, orarchaic(used before a present participle)in the act or process ofcome a-running; go a-hunting
- in the condition or state ofafloat; alive; asleep
- acre(s) or acreage
- the first letter in the Greek alphabet (Α, α), a vowel transliterated as a
- Britishthe highest grade or mark, as in an examination
- involving or relating to helium-4 nucleian alpha particle
- relating to one of two or more allotropes or crystal structures of a solidalpha iron
- relating to one of two or more isomeric forms of a chemical compound, esp one in which a group is attached to the carbon atom to which the principal group is attached
- (modifier)denoting the dominant person or animal in a groupthe alpha male
- Il, real name Agnolo di Cosimo . 1503–72, Florentine mannerist painter
- Scot variants of all
- (foll by the genitive case of a specified constellation)usually the brightest star in a constellationAlpha Centauri
- communicationsa code word for the letter a
- specific absorption coefficient
- systemic arterial blood (used as a subscript)
- total acidity
- alveolar gas (used as a subscript)
- AMP (in polynucleotides)
- The first letter of the Greek alphabet.
- The first one in a series; the beginning.
- The first position from a designated carbon atom in an organic molecule at which an atom or radical group may be substituted.
- Characterizing the atom or radical group that is closest to the functional group of atoms in an organic molecule.
- Relating to one of two or more closely related substances, as in stereoisomers.
- Relating to or characterizing a polypeptide chain that is one of five types of heavy chains present in immunoglobins.
- Without; not:acellular.
- Abbreviation of adenine, ampere, angstrom, area
- Abbreviation of angstrom
- A prefix meaning without or not when forming an adjective (such as amorphous, without form, or atypical, not typical), and absence of when forming a noun (such as arrhythmia, absence of rhythm). Before a vowel or h it becomes an- (as in anhydrous, anoxia).