Where does “tone sandhi” come from?

tone sandhi (English) comes from English tone, from Middle English tone, from Latin tonus, from Ancient Greek τόνος, from Proto-Hellenic tónos, from Proto-Indo-European tónos, from Proto-Indo-European ten- — to stretch, to extend.

tone sandhi (English): The change of tone that occurs in some tonal languages when certain tones are pronounced successively

Definitions

  1. The change of tone that occurs in some tonal languages when certain tones are pronounced successively

Ancestry of “tone sandhi”, step by step

tone sandhi traces back through two separate lines of ancestry.

via English tone

StepLanguageWordMeaning
1EnglishtoneA specific pitch; An interval of a major second;...
2Middle Englishtonethe one
3LatintonusThe stretching or straining of a rope; A strain;...
4Ancient Greekτόνοςrope, cord; chord; tone, note
5Proto-Hellenictónosrope, cord; tension
6Proto-Indo-Europeantónossomething stretched; chord, fiber, string
7Proto-Indo-Europeanten-to stretch, to extend

via English sandhi

StepLanguageWordMeaning
1EnglishsandhiAny of a wide variety of phonological processes...
2Sanskritसंधिcontaining a conjunction or transition from one...
3Sanskritसंधाto join, bring together, unite, combine, put together, compound, mix
4Sanskritसम्to be agitated or disturbed
5Sanskritआसto have been
6Proto-Indo-Europeansewh₁-to press, push
Every word from Proto-Indo-European ten-Every word from Proto-Indo-European tónosEvery word from Proto-Hellenic tónos