ADDITAMENT
Etymology
Noun
additament (plural additaments)
(archaic) An addition; something added. [from 14th c.]
And there are you perverting Nature in lying landscapes, filched from old rusty Titians, such as I can scrape up here to send you, with an additament from Shropshire nature thrown in to make the whole look unnatural.
Source: Wiktionary
Ad*dit"a*ment, n. Etym: [L. additamentum, fr. additus, p. p. of
addere to add.]
Definition: An addition, or a thing added. Fuller.
My persuasion that the latter verses of the chapter were an
additament of a later age. Coleridge.
Source: Webster’s Unabridged Dictionary 1913 Edition