Kamehameha also referred to as the Kamehameha Wave, is an "energy attack" in the manga Dragon Ball/Dragon Ball Z and the anime Dragon Ball, Dragon Ball Z and Dragon Ball GT.

The term was coined by the wife of author Akira Toriyama, in honor of Kamehameha the Great, a legendary conquerer of the Hawaiian Islands.

Within the context of the actual anime characters, the Kamehameha wave was created by Muten-Rôshi (Kame Sen'nin, known as Master Roshi in the English anime), and was taught to several of the Z Fighters of Earth, including Son Goku, Kuririn (Krillin), Son Gohan, Son Goten and Yamcha. Cell can also perform the Kamehameha due to having some of Goku's cells. Tenshinhan gained the ability to perform the Kamehameha wave when he observed it from Yamcha. This is Goku's signature attack.

The attack is performed by cupping the hands at the side of the body, usually the right, drawing them back and saying "KA - ME - HA - ME - HA" in five stages, before thrusting the hands forward and shooting a blue energy beam towards the target. Variations of this move include Goku's Instant Transmission Kamehameha, Gohan's one handed Kamehameha, and Goten's Kamekameha (Goten could not pronounce "Kamehameha" as a child).

Although every syllable is fully enunciated when performing the attack, in conversation characters tend to pronounce the word as a rapid "kameya-meya", as this is easier to say.

The name "kamehameha" is a pun in Japanese, since kame means "turtle" and Muten-Rôshi is the "Turtle Hermit".

Trivia

The Kamehameha Wave is very similar to Street Fighter's Ken and Ryu's Hadou-Ken