The antonyms for the word "prescribe" are "proscribe," "forbid," "abstain," "condemn," "disallow," "refuse," "prohibit," and "veto." Each of these words suggests a negative aspect of prescribing or prescribing something that is not safe or beneficial for an individual. Proscribing refers to the prohibition or elimination of something that is deemed harmful or illegal. Forbidding likewise suggests that something is not allowed or ought not to be done. Abstaining implies that someone is deliberately refraining from doing something. Condemning connotes a particularly harsh level of disapproval. Disallowing means to ban, refuse, or prohibit something. Refusing means to deny or reject a request or proposition.