"Break square" is an idiomatic expression used to describe when something is done fairly or honestly. It is similar in meaning to "play fair" or "act justly". There are several synonyms that can be used for this phrase, including "keep to the rules", "stick to the agreement", "adhere to the guidelines", or "follow the principles". All of these phrases convey a sense of fairness and honesty, suggesting that the rules or guidelines that have been established should be respected in order to ensure that everyone is treated equally. By using these synonyms in place of "break square", writers or speakers can convey the same meaning in a more varied and interesting way.