to refuse to allow (something); to refuse to allow (somebody) to do something
The law forbids shops to sell alcohol to minors
to refuse access to (somewhere) or use of (something)
Her father forbade him the house
to make (something) impracticable; to hinder or prevent (an action or expedient)
Limited time forbids further discussion of the subject
God/Heaven forbid
used to express a strong wish that something does not happen
Heaven forbid that my daughter inherits her dad's nose!
forbidder noun
[Old English forbēodan, from for- + bēodan to bid]