How many letters does the top answer for “wrote a suitable boy” have?

The most common answer is seth (4 letters).

Crossword clue: wrote a suitable boy

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

seth 4 letters wd-fact-v3

evil Egyptian god with the head of a beast that has high square ears and a long snout; brother and murderer of Osiris

author of a suitable boy 50% similar → seth

wrote astro boy 50% similar → tezuka

wrote beagle boys 50% similar → barks

wrote jo's boys 50% similar → alcott