addition

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or process of adding, especially the process of computing with sets of numbers so as to find their sum.
2. n. Something added, such as a room or section appended to a building.
3. idiom. in addition Also; as well.
4. idiom. in addition to Over and above; besides.

Century Dictionary and Cyclopedia

1. n. The act or process of adding or uniting, especially so that the parts remain independent of one another: opposed to subtraction or diminution: as, a sum is increased by addition; to increase a heap by the addition of more. Specifically, in arithmetic, the uniting of two or more numbers in one sum; also, that branch of arithmetic which treats of such combinations. Simple addition is the adding of numbers, irrespective of the things denoted by them, or the adding of sums of the same denomination, as pounds to pounds, ounces to ounces, etc. Compound addition is the adding of sums of different denominations, as pounds, shillings, and pence to pounds, shillings, and pence, like being added to like. The addition of all kinds of multiple quantity is performed according to the principle of compound addition; thus, the addition of two imaginary quantities is effected by adding the real parts together to get the new real part, and the imaginary parts to get the new imaginary part. Logical addition is a mode of combination of terms, propositions, or arguments, resulting in a compound (the sum), true if any of the elements are true, and false only if all are false.
2. n. The result of adding; anything added, whether material or immaterial.
3. n. Specifically— In law, a title or designation annexed to a man's name to show his rank, occupation, or place of residence: as, John Doe, Esq.; Richard Roe, Gent.; Robert Dale, Mason; Thomas Way, of Boston, Hence—
4. n. An epithet or any added designation or description: a use frequent in Shakspere, but now obsolete.
5. n. In music, a dot at the side of a note indicating that its sound is to be lengthened one half.
6. n. In heraldry, same as augmentation.
7. n. In distilling, anything added to the wash or liquor when in a state of fermentation.
8. n. Superaddition, appendage, adjunct, increase, increment, extension, enlargement, augmentation.
9. To furnish with an addition, or a designation additional to one's name.
10. To combine; add together.

Wiktionary

1. n. uncountable The act of adding anything.
2. n. Anything that is added.
3. n. uncountable The arithmetic operation of adding.

GNU Webster's 1913

1. n. The act of adding two or more things together; -- opposed to subtraction or diminution.
2. n. Anything added; increase; augmentation.
3. n. (Math.) That part of arithmetic which treats of adding numbers.
4. n. (Mus.), rare A dot at the right side of a note as an indication that its sound is to be lengthened one half.
5. n. (Law) A title annexed to a man's name, to identify him more precisely.; Richard Roe, Gent.; Robert Dale, Mason; Thomas Way, of New York; a mark of distinction; a title.
6. n. (Her.) Something added to a coat of arms, as a mark of honor; -- opposed to abatement.

WordNet 3.0

1. n. a quantity that is added
2. n. a suburban area laid out in streets and lots for a future residential area
3. n. a component that is added to something to improve it
4. n. the act of adding one thing to another
5. n. something added to what you already have
6. n. the arithmetic operation of summing; calculating the sum of two or more numbers