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):(compare hundreds of men); a dozen times (compare dozens of times). a hundred men
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.
a reduced, unstressed form of auxiliaryfollowing some modals, as might, should, could, would, and must (usually written as part of a single, unhyphenated word):Cf. of. We shoulda gone.
(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.
(sometimes l.c.) (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.
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.
(sometimes l.c.) the medieval Roman numeral for 50 or 500. Cf. Roman numerals.
(formerly) argon.
See
adenine.
alanine.
See
a designation for a motion picture recommended as suitable for adults. Cf. AA (def. 5),(def. 5),(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.
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).
an old point-action prefix, not referring to an act as a whole, but only to the beginning or end:(rose up). They abided by their beliefs (remained faithful to the end). She arose
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.