How many letters does the top answer for “do something to an excessive degree” have?

The most common answer is overdo (6 letters).

Crossword clue: do something to an excessive degree

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

overdo 6 letters wn-def

do something to an excessive degree

be or do something to a greater degree 60% similar → outdo, outgo, outmatch