What is the meaning of the word Kamehameha? In Wikipedia, Kamehameha is defined as a species of butterfly.


  kamehameha
  Web definitions
  The Kamehameha butterfly is one of the two species of butterfly native to Hawaii. The Hawaiian name is pulelehua. ...
  http://en.wikipedia.org/wiki/Kamehameha_(butterfly)


What does it mean in the Dragon Ball series?
According to Dragon Ball Wikia:


  Akira Toriyama actually tried a number of poses when he was alone in
  order to decide the coolest pose for the Kamehameha. After much
  contemplation, he could not decide on a name for his "Kame" attack, so
  he asked his wife who came up with the name. She told Akira that it
  would be easy to remember the name of the attack if he uses the name
  of the cultural Hawaiian king named Kamehameha (lit. "the very lonely
  one" or "the one set apart" in Hawaiian language). Also, Kamehameha
  means "Turtle Destruction Wave" in Japanese.


So, despite the literal translation in Japanese "Turtle Destruction Wave", Kamehameha is also a name of a Hawaiian king:


  Kamehameha I (Hawaiian pronunciation: [kəmehəˈmɛhə]; c. 1758 – May 8,
  1819), also known as Kamehameha the Great, conquered the Hawaiian
  Islands and formally established the Kingdom of Hawaiʻi in 1810. By
  developing alliances with the major Pacific colonial powers,
  Kamehameha preserved Hawaiʻi's independence under his rule. Kamehameha
  is remembered for the Kānāwai Māmalahoe, the "Law of the Splintered
  Paddle", which protects human rights of non-combatants in times of
  battle. Kamehameha's full Hawaiian name is Kalani Paiʻea Wohi o
  Kaleikini Kealiʻikui Kamehameha o ʻIolani i Kaiwikapu kauʻi Ka
  Liholiho Kūnuiākea.