ETYM Written also tabu.
Prohibition applied to magical and religious objects. In psychology and the social sciences the term refers to practices that are generally prohibited because of religious or social pressures; for example, incest is forbidden in most societies.
1. A prejudice (especially in Polynesia and other South Pacific islands) that prohibits the use or mention of something because of its sacred nature; SYN. tabu.
2. An inhibition or ban resulting from social custom or emotional aversion; SYN. tabu.

ETYM Written also tapu.
Forbidden to profane use especially in South Pacific islands; SYN. tabu.

To declare as sacred and forbidden.