How many letters does the top answer for “act of assisting or making easier the progress or improvement of something” have?

The most common answer is facilitation (12 letters).

Crossword clue: act of assisting or making easier the progress or improvement of something

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

facilitation 12 letters wn-def

act of assisting or making easier the progress or improvement of something