The phrase "turned a dime" is an idiom which means to suddenly change direction or attitude. There are many synonyms for this phrase that can be used in different contexts. Some of these synonyms include "changed course", "shifted gears", "altered direction", "took a new tack", "flipped the script", "swerved", "veered", "diverted", "changed tack", "changed one's tune", "did an about-face" and "made a U-turn". Each of these phrases can be used in a variety of situations where someone suddenly changes their opinion, direction or mindset, such as in politics, personal relationships, or even while driving a car.