ADDI'TION, n. [L. additio, from addo.]

1. The act of adding, opposed to subtraction, or diminution; as, a sum is increased by addition.

2. Any thing added, whether material or immaterial.

3. In arithmetic, the uniting of two or more numbers in one sum; also the rule or branch of arithmetic which treats of adding numbers. Simple addition is the joining of sums of the same denomination, as pounds to pounds, dollars to dollars. Compound addition is the joining of sums of different denominations, as dollars and cents.

4. In law, a title 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 New York.

5. In music, a dot at the side of a note, to lengthen its sound one half.

6. In heraldry, something added to a coat of arms, as a mark of honor, opposed to abatements, as bordure, quarter, canton, gyron, pile, &c. See these terms.

7. In distilling, any thing added to the wash or liquor in a state of fermentation.

8. In popular language, an advantage, ornament, improvement; that is, an addition by way of eminence.