An Etymological Dictionary of the German Language/schwätzen

by Friedrich Kluge

schwätzen, vb., ‘to chatter, prate, gossip,’ from the equiv. MidHG. swętzen, allied to MidHG. swaz (tz), ‘talking, chattering’; an intensive form of a Teut. root swaþ. Comp. MidHG. swadern, swatern, ‘to chatter, rustle, clatter,’ of which the simply ModHG. schwadronieren is a Rom. derivative. There is no relation to Lat. suadere. Origin obscure.