How many letters does the top answer for “preventing entry or exit or a course of action” have?

The most common answer is barricaded (10 letters).

Crossword clue: preventing entry or exit or a course of action

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

barricaded 10 letters wn-def

preventing entry or exit or a course of action

blockaded 9 letters wn-def

preventing entry or exit or a course of action