■ verb
1》 join to or put with something else.
2》 put together (two or more numbers or amounts) to calculate their total value.
↘( ~ up ) increase in amount, number, or degree.
↘( ~ up to ) amount to.
3》 ( ~ up ) informal make sense.
4》 say as a further remark.
Origin
ME: from L. ~it- , ~ere , from ad- 'to' + the base of dare 'put'.