look up any word, like bae:
 
1.
A surfing type of wave that is growing in size as you approach it. The bansai wave peaks and crashes on a surfers board or boat at the exact time to cause maximum damage and disorientation.

Bansai Wave is also known as a Suicide wave.
"Jesus John, dont paddle out yet, thats a bansai wave building out there."

"Bloody hell, i thought i was going to make that but just as i got there i realised it was a bansai wave. My head hurts now!"
by SwanseaCanoe February 26, 2010