archaism

archaism is a   Noun

Definition:

[1] An ancient, antiquated, or old-fashioned, word, expression, or idiom; a word or form of speech no longer in common use.

[2] Antiquity of style or use; obsoleteness. A select vocabulary corresponding (in point of archaism and remoteness from ordinary use) to our Scriptural vocabulary. De Quincey.

Synonyms: