Definition of "yahoo"

yahoo¹

/ˈjɑːhuː/

noun
plural yahoos
1. (derogatory) A rough, coarse, loud or uncouth person
2. (cryptozoology) A humanoid cryptid said to exist in parts of eastern Australia, and also reported in the Bahamas.
  Quotations
  The natives are greatly terrrified by the sight of a person in a mask calling him "devil" or Yah-hoo, which signifies evil spirit.
  1835, James Holman, Travels, quoted by Malcolm Smith, Bunyips and Bigfoots (Millennium Books, 1996, ), who notes that the Australian sense almost certainly derives from Gulliver's Travels, despite Holman's report
  1985, Michael Raynal, Yahoos in the Bahamas: Cryptozoology, volume 4

yahoo²

/jəˈhuː/

interjection
1. An exclamation of joy or enjoyment.
  Quotations
  "Yahoooooo! Give her some stick!"
  1959, Anthony Burgess, Beds in the East (The Malayan Trilogy), published 1972, page 521
2. A battle cry.
verb
third-person singular simple present yahoos, present participle yahooing, simple past and past participle yahooed
1. To give a cry of "yahoo".

yahoo³

verb
third-person singular simple present yahoos, present participle yahooing, simple past and past participle yahooed
1. (Internet, informal) To search using the Yahoo! search engine.
  Quotations
  Ah! You mean you have been 'yahooing'? I'm dead!
  2007, Tell
  I searched, Yahooed, Googled and everything else I could.
  2008, Frederick Thomas, Buddha's Bones, Buddha's Bones, page 46
  In other words, none of our googling and yahooing is private (you knew that, right ?).
  2017, Rajendra Pillai, Unearthed: Discover Life as God's Masterpiece, New Hope Publishers