Nouns

(n)taboo, tabua prejudice (especially in Polynesia and other South Pacific islands) that prohibits the use or mention of something because of its sacred nature
(n)taboo, tabuan inhibition or ban resulting from social custom or emotional aversion

Verbs

(v)taboodeclare as sacred and forbidden

Adjectives

(s)forbidden, out, prohibited, proscribed, taboo, tabu, verbotenexcluded from use or mention“forbidden fruit”, “in our house dancing and playing cards were out”, “a taboo subject”
(s)taboo, tabuforbidden to profane use especially in South Pacific islands