The phrase "cool it" is often used to tell someone to calm down or stop what they are doing. However, there are many synonyms that can be used in its place. For instance, "take it easy," "chill out," "relax," "calm down," "ease up," and "mellow out" are all excellent alternatives that convey a similar meaning. Other phrases that can be used include "cut it out," "knock it off," "slow down," and "settle down." These phrases can be used in various situations, such as when someone is angry, stressed, or agitated. Using any of these synonymous phrases can help de-escalate a tense situation and encourage others to take a step back and remain calm.