"Yackety" is a slang term that is often used to describe someone who is excessively talkative or chatty. While there are no direct synonyms for this particular word, there are several similar terms that can be used to convey a similar meaning. For example, "chatty," "garrulous," and "loquacious" are all words that can be used to describe a person who talks a lot. "Verbose," "windy," and "rambling" are terms that can be used to describe someone who talks excessively without getting to the point. Ultimately, the choice of synonym will depend on the context in which it is being used and the desired tone of the writing or conversation.