Definify.com
Webster 1913 Edition
Archaism
Ar′cha-ism
,Noun.
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.
Webster 1828 Edition
Archaism
'ARCHAISM
,Noun.
An ancient or obsolete phrase or expression.