How many letters does the top answer for “act of replacing one person or thing by another especially one held to be superior” have?

The most common answer is supersedure (11 letters).

Crossword clue: act of replacing one person or thing by another especially one held to be superior

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

supersedure 11 letters wn-def

act of replacing one person or thing by another especially one held to be superior

supersession 12 letters wn-def

act of replacing one person or thing by another especially one held to be superior