noun
archaism
AR-kee-i-zum/ˈɑːrkiɪzəm/
An old-fashioned feature of language or practice
The ancient temple-style entrance is an archaism on the modern glass building.

Etymology
“Copying the ancients” underlies the earlier sense of retaining old or obsolete forms. Archaism then came to name an individual example of such retention: an old-fashioned word, expression, or stylistic feature.
In context
that is now little more than a cherished archaism of the kind so beloved of the British despite ourselves.
More examples
- The poem deliberately uses archaisms to evoke the past.
- That legal phrase is a surviving archaism.
- The novelist avoids unnecessary archaism in contemporary dialogue.
Forms
archaism · archaisms
Similar words
- anachronism
- Belongs to the wrong historical period, not merely an older usage.
- obsolete expression
- No longer current, whereas an archaism may survive deliberately.