milliarium
/mɪlɪˈɛːrɪəm/(also miliarium) Roman History
noun
In full golden milliarium: a gilded stone pillar erected during the reign of Augustus in the Forum in Rome below the temple of Saturn, and from which distances from Rome were calculated. Hence: a pillar or other marker serving a similar purpose in another city of the Roman Empire.
Origin
Late 16th century; earliest use found in Henry Savile (1549–1622), mathematician and classical scholar. From classical Latin mīliārium, mīlliārium.