late 14c., "action of adding numbers;" c. 1400, "that which is added," from Old French adition "increase, augmentation" (13c.), from Latin additionem (nominative additio) "an adding to, addition," noun of action from past participle stem of addere (see add). Phrase in addition to "also" is from 1680s.
1. In addition to my weekly wage, I got a lot of tips.
2. In addition, the respondent disclosed professional confidences to one of the patients.
3. This plywood addition helps to strengthen the structure.
4. She's ready to learn simple addition and subtraction.