What is "Jai Dam" in Thai?
Literally I take it to mean 'heart black' but am not sure what that means to a Thai person exactly.
Is "Jai Rohn"-hot headed and "Jai Dee"-kind?

Question

Answer

Aloha ha ha ha .......Jai Dam is used when someone is being cold.

Answer

sawaddee ka, Jai Dam means unsympathetic, pitiless, selfish, wicked, mean, merciless. 
Actually, Thai people use this word,, when you would like someone help you something but she or he refuse to help you without good reasonable...(kao jai mai ka? Do you get it?) 

From English Beginner ...

Não perca a oportunidade de aprender uma língua no conforto da sua casa. Navegue pela nossa seleção de professores de línguas experientes e inscreva-se na sua primeira aula agora mesmo!