di·a·chron·ic
adjective/ˌdaɪəˈkrɒnɪk/
/ˌdaɪəˈkrɑːnɪk/
(specialist)- relating to the way something, especially a language, has developed over time
（尤指语言研究）历时的 Word Originmid 19th cent.: from dia- ‘through’ + Greek khronos ‘time’ + -ic.