A phrase created by the Youtuber/Twitch streamer, TerryTV. It is generally used towards someone who is acting a little crazy, over the top, extra, or simply just really hyper. Basically telling someone to calm down. Can be used in other situations where one should "chill out". It's used in a playful way.
Person 1: Omg I think my neighbor is stalking me.
Person 2: Calm thyself, he's just saying hello.

Person 1: I think my teacher saw me cheating on my test!

Person 2: Calm thyself, he was looking at his computer the whole time.

Person 1: I am so hot
Person 2: *laughs* calm thyself
by LetsWatchTheRain August 4, 2020
Get the Calm Thyself mug.