ETYM Latin, from addere to add.
(Irregular plural: addenda).
Textual matter that is added onto a publication; usually at the end; SYN. supplement, postscript.
Something added; appendix.
(Latin) Something to be added, usually in writing, which qualifies a foregoing thesis or statement.

ETYM French addition, Latin additio, from addere to add.
1. A component that is added to something to improve it; SYN. improver.
2. A quantity that is added; SYN. increase, gain.
3. A suburban area laid out in streets and lots for a future residential area.
4. The act of adding one thing to another.
In arithmetic, the operation of combining two numbers to form a sum; thus, 7 + 4 = 11. It is one of the four basic operations of arithmetic (the others are subtraction, multiplication, and division). + prikaži više

ETYM French supplément, Latin supplementum, from supplere to fill up. Related to Supply.
A quantity added; e.g. to make up for a deficiency.