Kamehameha (Dragon Ball)
The Kamehameha, sometimes known as the Kamehameha Wave, is a powerful attack technique developed by Master Roshi. The user cups their hands together and holds them to their side, charging the ki for the attack, then releases it as a blast of blue energy. The phrase "Ka-me-ha-me-ha" is customarily said while the attack is being made, but that isn't necessary every time. Even with weaker fighters, the attack can shatter mountains; an experienced fighter can redirect the blast at moving targets, or even use it to achieve effective flight as well.
It took Roshi decades to develop the attack, but Goku learned it after a few minutes. The attack was later taught to Krillin, Yamcha, Gohan, Goten and Uub. Cell and Majin Buu were also capable of imitating the attack.
The attack supposedly means "Turtle Destruction Wave" in Japanese, a reference to Roshi's other name (Kamesennin or "Turtle Hermit"). It was named by Dragon Ball creator Akira Toriyama from a suggestion by his wife.