An Explosion and Implosion that happen at the exact same time, causeing the object to remain exactly the same. All you would see would be a puff of smoke.
Commonly said during a disagreement of ideas in which there is no rebuttal and signifies the speaker's victory. The term was first said in a discussion about the Big Bang or the end of the world. (I think...)
Uncle Kenny: The human race will die off long before the earth. Earth will continue existing until the sun explodes.
Commonyoshi: Not if it implodes.
or
Zook: Weedle is the coolest pokemon ever.
Commonyoshi: Not if it implodes.
Zook: Dammit!
When you overheat pizza rolls in the microwave and then stuff them up your girl's vag, only to then stomp down on her abdomen as hard as you can so they explode out of her pussy hole giving her third degree burns.