When it comes to being unrestricted or uncontrolled, there are several synonyms one can use for the term "not restrained." For instance, "unbridled" describes something that is not constrained or inhibited by rules, principles, or laws. "Unrestrained" is another term you can use to signify that something is not limited or held back. "Unhampered" means to be free of obstruction or hindrance, while "unfettered" refers to something that is free from restraints or restrictions. Lastly, "limitless" is another synonym you can use for the term "not restrained," which means something has no boundaries or limits. There are plenty of synonyms you can use to convey the idea of being "not restrained," depending on your specific intent and tone.