How many letters does the top answer for “director of dumbo” have?

The most common answer is arkin (5 letters).

Crossword clue: director of dumbo

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

arkin 5 letters wd-fact-v3

keaton 6 letters wd-fact-v3

United States comedian and actor in silent films noted for his acrobatic skills and deadpan face (1895-1966)

director of 9-1-1 50% similar → bassett

director of 90210 50% similar → grimes

director of her 50% similar → phoenix

director of q13415681 50% similar → hamill

director of q20856802 50% similar → gosling

director of q23685878 50% similar → levi

director of q60102 50% similar → adlon, shalhoub

director of q79784 50% similar → cox