It is to the credit of 18th-century British navigator and explorer Capt. James Cook that the word "taboo" — derived from the Tongan tapu or Fijian tabu and variously meaning consecrated, inviolable, forbidden, unclean or cursed — became part of the English language.
By the Meiji Period a century later, "taboo" had found its way into Japanese. Sanseido's Dictionary of Katakana Words (1998 edition) defines tabū as 1) "a religiously forbidden practice among primitive tribes"; and 2) "by extension, things that are forbidden, banned or which may not be spoken about."
Taboos, of course, have existed in every human culture. When referring to Buddhist proscriptions, for instance, Japanese use the term kinmotsu, literally "a banned thing."