The "mad decade" refers to the 1960s, a time of sweeping social, cultural, and political change. However, there are a few antonyms that come to mind when describing this era. One is "mellow," which brings to mind a more laid-back and peaceful time. Another is "stable," alluding to a time of calm and consistency. Additionally, "conservative" stands in stark contrast to the liberal and progressive movements of the 60s. Lastly, "quiet" may be used to describe a time without the social unrest and protests that characterized the "mad decade." While these antonyms describe a different time period, they help us to contrast the active, dynamic, and sometimes tumultuous changes that took place in the 1960s.