How many letters does the top answer for “acting together, as agents or circumstances or events” have?

The most common answer is concurrence (11 letters).

Crossword clue: acting together, as agents or circumstances or events

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

concurrence 11 letters wn-def

acting together, as agents or circumstances or events

concurrency 11 letters wn-def

acting together, as agents or circumstances or events