Definition

An abbreviated form of the archaic "forsooth," used ironically by people who want to sound medieval or whimsically old-timey. It's essentially "truth" or "for real" but dressed in Renaissance faire cosplay.

Example Usage

You actually read the terms and conditions? Sooth!

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=sooth&defid=20693)