Which term best describes the act of bringing a topic up for discussion?

The term that best describes the act of bringing a topic up for discussion is "broach." To broach a topic means to introduce or raise it for consideration, especially when it may be a sensitive or important subject. This usage captures the essence of initiating dialogue, which is essential in conversations, negotiations, or when addressing critical issues.

The term is particularly relevant in contexts where a delicate or significant matter needs to be approached thoughtfully and can imply that the subject may not be easy to discuss. This aspect of broaching a topic is critical in many interpersonal and professional interactions where effective communication is vital.

In contrast, the other options do not relate to initiating dialogue in the same way. "Avow" relates to openly declaring or affirming something, often with a sense of personal sentiment or belief, rather than introducing a topic. "Baneful" refers to something causing harm or destruction, which does not connect to the act of discussion. "Antithetical" describes something that is directly opposed or contrasted to something else, but it doesn’t capture the action of bringing something up for dialogue.