From WordNet (r) 3.0 (2006):
taboo
adj 1: excluded from use or mention; "forbidden fruit"; "in our
house dancing and playing cards were out"; "a taboo
subject" [syn: forbidden, out(p), prohibited,
proscribed, taboo, tabu, verboten]
2: forbidden to profane use especially in South Pacific islands
[syn: taboo, tabu]
n 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: taboo,
tabu]
2: an inhibition or ban resulting from social custom or
emotional aversion [syn: taboo, tabu]
v 1: declare as sacred and forbidden