ETYM Old Eng. frothe, Icel. frotha; akin to Dan. fraade, Swed. fradga, AS. âfreothan to froth.
1. The bubbles caused in fluids or liquors by fermentation or agitation; spume; foam.
2. Light, unsubstantial matter.

1. To cause to foam.
2. To spit, vent, or eject, as froth.
3. To cover with froth.