Archaism
Pronunciation : Ar"cha*ism
Part of Speech : n.
Etymology : [Gr. archa?sme. See Arch, a.]
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.
Source : Webster's Unabridged Dictionary, 1913