a

1. A roughly bounded part of the space on a surface; a region: a farming area; the New York area.

2. A surface, especially an open, unoccupied piece of ground: a landing area; a playing area.

3. A distinct part or section, as of a building, set aside for a specific function: a storage area in the basement.

4. A division of experience, activity, or knowledge; a field: studies in the area of finance; a job in the health-care area.

5. An open, sunken space next to a building; an areaway.

6. Abbr. A The extent of a planar region or of the surface of a solid measured in square units.

7. Computer Science A section of storage set aside for a particular purpose.

1. A unit of electric current in the meter-kilogram-second system. It is the steady current that when flowing in straight parallel wires of infinite length and negligible cross section, separated by a distance of one meter in free space, produces a force between the wires of 2 × 10^-7 newtons per meter of length.

2. A unit in the International System specified as one International coulomb per second and equal to 0.999835 ampere. See Table at measurement.

1. A low female singing voice; a contralto.

2. A countertenor.

3. 1. The range between soprano and tenor.

   2. A singer whose voice lies within this range.

   3. An instrument that sounds within this range.

   4. Abbr. A A vocal or instrumental part written in this range.

1. 1. The act of accelerating.

   2. The process of being accelerated.

2. Abbr. a Physics The rate of change of velocity with respect to time.

1. accusative

2. Games ace

3. across

4. adenine

5. alto

6. ampere

7. or Å angstrom

8. area

1. acceleration

2. are (measurement)

1. Used before nouns and noun phrases that denote a single but unspecified person or thing: a region; a person.

2. Used before terms, such as few or many, that denote number, amount, quantity, or degree: only a few of the voters; a bit more rest; a little excited.

3. 1. Used before a proper name to denote a type or a member of a class: the wisdom of a Socrates.

   2. Used before a mass noun to indicate a single type or example: a dry wine.

4. The same: birds of a feather.

5. Any: not a drop to drink.

Usage Note: In writing, the form a is used before a word beginning with a consonant sound, regardless of its spelling (a frog, a university). The form an is used before a word beginning with a vowel sound (an orange, an hour). · An was once a common variant before words beginning with h in which the first syllable was unstressed; thus 18th-century authors wrote either a historical or an historical but a history, not an history. This usage made sense in that people often did not pronounce the initial h in words such as historical and heroic, but by the late 19th century educated speakers usually pronounced initial h, and the practice of writing an before such words began to die out. Nowadays it survives primarily before the word historical. One may also come across it in the phrases an hysterectomy or an hereditary trait. These usages are acceptable in formal writing.

1. The first letter of the modern English alphabet.

2. Any of the speech sounds represented by the letter a.

3. The first in a series.

4. Something shaped like the letter A.

5. A The best or highest in quality or rank: grade A milk.

6. Music

   1. The sixth tone in the scale of C major or the first tone in the relative minor scale.

   2. A key or scale in which A is the tonic.

   3. A written or printed note representing this tone.

   4. A string, key, or pipe tuned to the pitch of this tone.

7. A One of the four major blood groups in the ABO system. Individuals with this blood group have the A antigen on the surface of their red blood cells, and the anti-B antibody in their blood serum.