Pronunciation: (ā), [key]
—pl. A's or As, a's or as.
1. the first letter of the English alphabet, a vowel.
2. any spoken sound represented by the letter A or a, as in bake, hat, father, or small.
3. something having the shape of an A.
4. a written or printed representation of the letter A or a.
5. a device, as a printer's type, for reproducing the letter A or a.
6. from A to Z, from beginning to end; thoroughly; completely: He knows the Bible from A to Z.
7. not know from A to B, to know nothing; be ignorant.
Pronunciation: (u; when stressed ā), [key]
1. not any particular or certain one of a class or group: a man; a chemical; a house.
2. a certain; a particular: one at a time; two of a kind; A Miss Johnson called.
3. another; one typically resembling: a Cicero in eloquence; a Jonah.
4. 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).
5. indefinitely or nonspecifically (used with adjectives expressing number): a great many years; a few stars.
6. one (used before a noun expressing quantity): a yard of ribbon; a score of times.
7. any; a single: not a one.
Pronunciation: (u; when stressed ā), [key]
each; every; per: ten cents a sheet; three times a day.
Pronunciation: (u), [key]
Pron. Spelling.a reduced, unstressed form of of (often written as part of a single, unhyphenated word): cloth a gold; time a day; kinda; sorta.
Pronunciation: (u), [key]auxiliary verb.
Pron. 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. Cf. of2.
Pronunciation: (u, a, ä), [key]
1. Brit. Dial.
Pronunciation: (ä, ô), [key]
Scot.all: for a' that. Also,a.
1. Elect.ampere; amperes.
4. Brit.arterial (used with a road number to designate a major highway): Take the A525 to Ruthin.
1. the first in order or in a series.
2. (sometimes l.c.) (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.
3. (sometimes l.c.) (in some school systems) a symbol designating the first semester of a school year.
a. the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor.
b. a string, key, or pipe tuned to this tone.
c. a written or printed note representing this tone.
d. (in the fixed system of solmization) the sixth tone of the scale of C major, called la.
e. the tonality having A as the tonic note.
5. Physiol.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. Cf. ABO system.
6. (sometimes l.c.) the medieval Roman numeral for 50 or 500. Cf. Roman numerals.
7. Chem.(formerly) argon.
8. Chem., Physics.See mass number.
10. Logic.See universal affirmative.
11. Brit.a designation for a motion picture recommended as suitable for adults. Cf. AA (def. 5), U (def. 5), X (def. 9).
12. a proportional shoe width size, narrower than B and wider than AA.
13. a proportional brassiere cup size, smaller than B and larger than AA.
14. a quality rating for a corporate or municipal bond, lower than AA and higher than BBB.
atomic (used in combination): A-bomb; A-plant.
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).
var. of ab- before p and v: aperient; avert.
var. of ad-, used: (1) before sc, sp, st (ascend) and (2) in words of French derivation (often with the sense of increase, addition): amass.
var. of an- 1 before a consonant, meaning “not,” “without”: amoral; atonal; achromatic.
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.
3. acre; acres.
2. acre; acres.
6. ampere; amperes.
11. are; ares.
12. Baseball.assist; assists.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.