What does "diachrony" mean?

The study of change over time, especially changes to language.

What is a synonym for "diachrony"?

Common synonyms include: diachronic linguistics, historical linguistics.

Pronounced //daɪˈækɹəni//.

/daɪˈækɹəni/ noun

noun ·Rare ·Advanced level

Noun

1
The study of change over time, especially changes to language. uncountable, usually
2
the study of linguistic change wordnet

"Japan fans may like the article "Diachrony of complex predicates in Japanese.""

By surface analysis, dia- + chron- + -y; historically, see synchronous § Etymology.