Movie director Michael Bay's mind set. Taken from Robot Chicken. The "Ma" stands for 'Michael', the "Ba" for 'Bay' and the "sploom" is a shortening of "'splosion" and "boom".
Watch his films for an example. They're pretty much just Michael Bay playing with his toys while screaming "Ma Ba SPLOOM!"
A large explosion of some variety, usually stemming from a Michael Bay scene.
Whoa! Did you see that??!? It was all like "MA BA SPLOO!"
I bet you two horse hooves you got half way through the word and realized it's the opening theme song for The Lion King
Naaaants een-vwen-yaaaaaaa ma-ba-gee-chi-ba-va YOU A GAY NIGGA.