There are various synonyms for the word "yakker" including chatterbox, gossip, blabbermouth, talker, and gabber. A yakker is typically someone who talks excessively and often about trivial matters that may not interest others. A chatterbox tends to talk non-stop, while a gossip shares information or rumors about people. A blabbermouth is someone who reveals personal or confidential information without permission. A talker is simply a person who enjoys talking and conversing with others. A gabber talks incessantly and often without much thought. Overall, all these terms describe someone who talks excessively or without restraint, often resulting in others becoming annoyed or disinterested.