adjective
verboten
ver-BOH-tun/vərˈbəʊtn/
Not allowed by a rule or custom.
Touching the sculpture is verboten, and the attendant stops the visitor’s hand.

Etymology
The German verb meaning “to forbid” supplies the participle meaning “forbidden.” Its kinship with English forbid makes the two words historical relatives as well as close matches in meaning.
In context
these topics that are verboten you will not speak of you will not contradict
More examples
- The subject seemed verboten at family dinners.
- Unauthorized changes are verboten under the rules.
- He treated any criticism as verboten.
Forms
verboten
Similar words
- forbidden
- Forbidden is the ordinary English equivalent; verboten often adds emphatic or slightly playful force.
- taboo
- Taboo suggests a strong social prohibition; verboten can refer to any imposed rule.