Anachronism
Etymology
From Greek ana-, "against, back," plus chronos, "time," combined into anachronismos, "a mistake in time." The literal sense is something set against its proper time. It arrived in English in the seventeenth century, first for errors of dating in history and art, then for anything comically or poignantly out of its age.
noun · /uh-NAK-ruh-niz-uhm/
Something placed in the wrong period of time, or a thing that seems to belong to another era.
What it names
The name for a chronological mismatch — a wristwatch in a Roman epic, or a person clinging to customs the world has left behind.
Example
With its wax seals and inkwells, the firm felt like an anachronism, a fragment of the nineteenth century still billing by the hour.
Related idea
Vestige is a genuine leftover trace from the past that survives into the present; an anachronism is anything that seems misplaced in time, including things wrongly inserted into a period they never belonged to.