The term "callboy" is typically used to refer to a young male employed to summon performers or help actors backstage in the theater industry. However, there are many synonyms for this word that can be used in different contexts. For example, "page" and "runner" are both commonly used for someone who delivers messages or runs errands. "Assistant" and "attendant" are other possible alternatives, indicating a role that involves serving someone else's needs or providing support. A "dispatch rider" is similar to a callboy, but specifically refers to someone who delivers messages by motorcycle or bicycle. Overall, there are many options for anyone who needs to replace the word "callboy" in a sentence or conversation.