How many letters does the top answer for “the act of increasing (something) in size or volume or quantity or scope” have?

The most common answer is enlargement (11 letters).

Crossword clue: the act of increasing (something) in size or volume or quantity or scope

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

enlargement 11 letters wn-def

the act of increasing (something) in size or volume or quantity or scope

expansion 9 letters wn-def

the act of increasing (something) in size or volume or quantity or scope