"Yack away" is a colorful expression that generally means to talk excessively or in a way that is considered annoying or pointless. However, there are several synonyms for this phrase that can convey a similar meaning. Some of these include "babble on," "prattle," "chatter incessantly," "ramble," "jabber," "go on and on," and "drone on." Each of these synonyms carries a slightly different connotation, with some emphasizing a lack of focus or coherence, while others suggest a more persistent and grating tone. Regardless of the word chosen, the underlying message remains the same: someone is talking a lot, and you're struggling to stay engaged.