The term 'SOURCE OF SUDS' can be broken down into four separate solutions: TAP (3 letters), KEG (3 letters), SOAP (4 letters), and BREWPUB (7 letters). TAP is a device used to dispense beer, wine, or other beverages from a cask or KEG. KEG is a cylindrical container made of metal or plastic that holds beer or other carbonated beverages. SOAP is a cleansing agent made from the salts of vegetable or animal fats. Lastly, a BREWPUB is a pub or restaurant that brews its own beer on the premises.