From chrono- + -lect.

• IPA: /ˈkɹɒnəʊlɛkt/

chronolect (plural chronolects)

1. (linguistics, sociolinguistics) A specific variety of a language at a given time in its history of development.

   Koine and Byzantine Greek are chronolects of Greek.

   • 1981, Leuvense Bijdragen, volume LXX, Martinus Nijhoff Publishers, page 52 ↗:

     Taking lect in the sense of ‘variety’ (and not ‘social variety’), I have coined spatiolect ‘spatial variety’, chronolect ‘chronological variety’, communolect ‘variety of a community (however defined)’, ecolect ‘variety of an economic class’, ethnolect ‘variety of an ethnic group’, religiolect ‘variety of a religious group’, sexlect ‘variety of one of the sexes or of people with a certain sexual orientation’, urbolect ‘urban variety’, and rurolect ‘rural variety’.