bubble (n.)
early 14c., perhaps from Middle Dutch bobbel (n.) and/or Middle Low German bubbeln (v.), all probably of echoic origin. Bubble bath first recorded 1949. Of financial schemes originally in South Sea Bubble (1590s), on notion of "fragile and insubstantial."
bubble (v.)
mid-15c., perhaps from bubble (n.) and/or from Middle Low German bubbeln (v.), probably of echoic origin. Related: Bubbled; bubbling.