The term 'Tavern Mugful' is a combination of two crossword solutions: ALE (3 letters) and BEER (4 letters). ALE is an alcoholic beverage made from malted barley, hops, yeast, and water. It is usually top-fermented and has a slightly bitter taste. BEER is also an alcoholic beverage made from malted barley, hops, yeast, and water. It is usually bottom-fermented and has a milder flavor than ALE. A tavern mugful is a combination of both ALE and BEER, typically served in a large mug.