How many letters does the top answer for “wrote rear window” have?

The most common answer is hitchcock (9 letters).

Crossword clue: wrote rear window

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

hitchcock 9 letters wd-fact-v3

English film director noted for his skill in creating suspense (1899-1980)

stewart 7 letters wd-fact-v3

Scottish philosopher and follower of Thomas Reid (1753-1828)

author of rear window 50% similar → hitchcock, stewart