The phrase "call it quits" generally means to stop doing something or to end a relationship or situation. It can also be used to signify that a decision has been made to end things and move on. Many phrases can be used as synonyms for this expression, including "throw in the towel," "give up," "cease," "halt," "discontinue," and "withdraw." Other similar phrases include "end it," "wrap it up," "put an end to it," "bring to a close," and "finish it off." All of these phrases convey the idea of bringing something to an end and moving on to another chapter in one's life.