additionist

== English == === Etymology === From addition +‎ -ist. === Noun === additionist (plural additionists) (rare) One who supports or implements a policy of adding something. Jeff Riggenbach, Why American History Is Not What They Say (page 85) He was, he said, an "additionist"— the fellow who comes along after the historical accounts have been written and adds what's been (inadvertently or deliberately) left out.