From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Instant Kamehameha (瞬間 かめはめ波, Shunkan Kamehameha; FUNimation "Instant Kamehameha"; Literally meaning "Moment Turtle Destruction Wave") is a combination of the Instant Transmission and the Kamehameha and used by Son Goku in his Super Saiyan form.
First, Super Saiyan Goku charges up the Kamehameha by saying, "Ka... me... ha... me..." Next, he uses the Instant Transmission to teleport in front of his opponent while he is still charging the attack. Finally, Super Saiyan Goku fires the attack with the final syllable, "...Ha!" at his opponent, inflicting an enormous amount of damage.
Super Saiyan Goku used this attack in his fight against Perfect Cell. The astounding, sheer power put into the blast was powerful enough to literally vaporize the top half of Perfect Cell's body. Due to having Piccolo's regenerative ability in his cells, however, Perfect Cell was able to regenerate his torso and continue the fight.
Goku later used this move to defeat Pikkon after figuring out the weakness of his Thunder Flash Attack. Goku teleported to Pikkon's side rather than in front of him, however, to blast him off of the arena.
When Super Saiyan Goku (End) uses the Instant Kamehameha in Dragon Ball Z: Budokai Tenkaichi 3 and Dragon Ball Z: Budokai Tenkaichi 2, it functions in the same way as in the anime and is fully unblockable (though it can sometimes be dodged with perfect timing).
It is named Shunkan Idō Kamehameha (瞬間 移動 かめはめ波, Shunkan Idō Kamehameha) in Miracle Battle Carddass Dragon Ball Z Kai.
It is named Shunkan Idō Kamehameha (瞬間 移動 かめはめ波, Shunkan Idō Kamehameha) in Dragon Ball: Daizenshū 7.
- 瞬 (shun) = instantaneous/instant
- 間 (kan) = between
- 瞬間 (shunkan) = moment
- Sean Schemmel, the most well-known English voice actor of Goku, has stated that the scene where Goku uses the Instant Kamehameha against Cell is his favorite scene.