There are several synonyms for the phrase "refrain from action." Some common ones include "abstain," "withhold," "restrain," "hold back," and "avoid." These synonyms all convey the idea of intentionally not taking a specific course of action. "Abstain" is often used in the context of refraining from a particular behavior, such as drinking alcohol or smoking. "Withhold" can be used in situations where someone is holding back information or resources. "Restrain" is often used in more physical situations, such as restraining oneself from physically lashing out in anger. "Hold back" is similar to "restrain" but can also be used in situations where someone is holding back their emotions or opinions. And "avoid" is often used when someone is deliberately staying away from a potentially problematic situation.