Where does “ความเท่” come from?

ความเท่ (Thai) comes from Thai ความ, from Proto-Tai ɣwaːmᴬ — matter.

Ancestry of “ความเท่”, step by step

ความเท่ traces back through two separate lines of ancestry.

via Thai ความ

StepLanguageWordMeaning
1Thaiความaffair; matter; content; essence; subject;...
2Proto-Taiɣwaːmᴬmatter

via Thai เท

StepLanguageWordMeaning
1Thaiเทto pour; to move like a stream: to flow, to...
Every word from Proto-Tai ɣwaːmᴬEvery word from Thai ความ