Sepuku is when a ninja butters or greases up a frisbee,bends in in half and inserts it into his mouth.
"Hurooo the ninja commited Sepuku and didnt even think about it."
by Daric April 25, 2006
A ritual suicide practiced by samurai in Japan, usually because he has brought shame and dishonor to himself. This might have resulted from failing to protect his master, or otherwise breaking the code of bushido, "the way of the warrior". The soon-to-be-deceased kneels with a short sword in both hands, and disembowels himself. Immediately after this, the sepuku assisant, known as the kaishakunin or "second", beheads the person with a sword. The ritual goes into great detail about washing and dressing, last words, etc.
The disgraced samurai was asked to commit sepuku by his superiors.
by midget_rodeo August 19, 2006
Sepuku is the act of commiting Honorable Suicide. A defeated samurai warrior would kill himself before allowing his opponent the honor of finishing him off. Also See: HaraKiri.
Defeated Samurai jabs his Tanto (The smaller of the two swords carried) into his stomach/chest.
by William March 10, 2005