How many letters does the top answer for “the perception that something has occurred or some state exists” have?

The most common answer is detection (9 letters).

Crossword clue: the perception that something has occurred or some state exists

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

detection 9 letters wn-def

the perception that something has occurred or some state exists

sensing 7 letters wn-def

the perception that something has occurred or some state exists