Where does “ความบ้า” come from?

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

Ancestry of “ความบ้า”, step by step

ความบ้า traces back through two separate lines of ancestry.

via Thai ความ

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

via Thai บ้า

StepLanguageWordMeaning
1Thaiบ้าcrazy, mad, insane; a name of fish, "Leptobarbus...
2Proto-Taiɓaːᶜcrazy
Every word from Proto-Tai ɣwaːmᴬ →Every word from Thai ความ →