Where does “ความใจดำ” come from?

ความใจดำ (Thai) comes from Thai ใจดำ, from Thai ใจ, from Proto-Tai cɤɰᴬ — heart; breath.

Ancestry of “ความใจดำ”, step by step

ความใจดำ traces back through two separate lines of ancestry.

via Thai ใจดำ

StepLanguageWordMeaning
1Thaiใจดำmerciless, heartless, pitiless; inconsiderate, unfeeling, unsympathetic; ungenerous, selfish
2Thaiใจheart; mind; spirit; breath
3Proto-Taicɤɰᴬheart; breath

via Thai ความ

StepLanguageWordMeaning
1Thaiความaffair; matter; content; essence; subject;...
2Proto-Taiɣwaːmᴬmatter
Every word from Proto-Tai cɤɰᴬ →Every word from Thai ใจ →Every word from Thai ใจดำ →