The phrase "another's action boob" refers to a mistake or error made by someone else, which can be embarrassing or frustrating, especially when it affects you in some way. There are several synonyms for this phrase, including blunder, mistake, stumble, slip-up, error, goof, gaffe, faux pas, oversight, and flub. These words all describe different types of mistakes, ranging from simple slip-ups to more significant errors that can have serious consequences. Using synonyms for "another's action boob" can help you communicate more effectively and convey the exact nature and severity of the mistake or error in question.