How many letters does the top answer for “the quantity that can be held in a mug” have?

The most common answer is mugful (6 letters).

Crossword clue: the quantity that can be held in a mug

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

mugful 6 letters wn-def

the quantity that can be held in a mug

the quantity that can be held in the hand 60% similar → fistful, handful

the quantity that can be held in the lap 60% similar → lapful

the quantity that can be held in the mouth 60% similar → mouthful