i dont know about split the dummy, but spit the dummy means to get mad about something.
dummy
If you mean dummy, like a manikin, I can't answer that. If you mean dummy, like idiot, the Japanese way to say it is baka. (ba-ka).
If someone calls you a dummy, it can mean: You're stupid You're silly You're unintelligent You're foolish
No dummy
dummy this dummy that hard questions no answers
baka, it means idiot or moron but it can mean dummy. Same thing really...
it means stupid dummy
It is a crust dummy
it means hoe dummy!
a dummy
It means wide receiver. Dummy
no dummy