One of the mysteries of the English language finally explained.
1rare Something that is added, an addition; an additive. rare.
historical Immunology= "complement". Now chiefly historical.
Mid 17th century; earliest use found in Peter Heylyn (1599–1662), Church of England clergyman and historian. Apparently a shortening of additament.
In this article we explore how to impress employers with a spot-on CV.