How many letters does the top answer for “who was the british prime minister at the outbreak of the second world war” have?

The most common answer is chamberlain (11 letters).

Crossword clue: who was the british prime minister at the outbreak of the second world war

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

chamberlain 11 letters otdb

an officer who manages the household of a king or nobleman

neville 7 letters otdb