David Filo and Jerry Yang developed the first online navigational guide to the Internet while attending Stanford University. They originally called it Jerry's Guide to the World Wide Web. The two students developed a means to bookmark and categorize their favorite web sites. Today, Yahoo!, an acronym for Yet Another Hierarchical Officious Oracle, provides custom searching to nearly 220 million people each month.
ya·hoo1 / ˈyäˌhoō; yäˈhoō/ • n. inf. a rude, noisy, or violent person.ya·hoo2 / yäˈhoō/ • interj. expressing great joy or excitement.
From the mid 19th century yahoo (perhaps a different word in origin) has also been used in Australia for a mythical creature resembling a big hairy man, said to haunt eastern Australia.