- To combine (a column of figures, for example) to form a sum.
- To join or unite so as to increase in size, quantity, quality, or scope: added 12 inches to the deck; flowers that added beauty to the dinner table.
- To say or write further.
- To find a sum in arithmetic.
- To constitute an addition: an exploit that will add to her reputation.
- To create or make an addition: gradually added to my meager savings.
- add up To be reasonable, plausible, or consistent; make sense: The witness's testimony simply did not add up.
- add up To amount to an expected total: a bill that didn't add up.
- add up To formulate an opinion of: added up the other competitors in one glance.
- add up to To constitute; amount to: The revisions added up to a lot of work.