ARCHAISM: A word, expression, spelling, or phrase that is out of date in the common speech of an era, but still deliberately used by a writer, poet, or playwright for artistic purposes. For instance, two archaic words (reproduced here in italics) appear in these lines from Coleridge's The Rime of the Ancient Mariner:
"Hold off! unhand me, grey-beard loon!"
Eftsoons his hand dropt he.