To join or unite into one sum or aggregate.To unite, join, attach, annex, or subjoin as an augmentation or accretion; bring into corporate union or relation: with to before the subject of addition, and sometimes without an expressed object when this is implied by the subject: as, add another stone, or another stone to the pile; he continually addedto his store; to add to one's grief.To put into the possession of; give or grant additionally, as to a person.To be or serve as an addition; be added: with to: as, the consciousness of folly often adds to one's regret.To perform the arithmetical operation of addition.