How many letters does the top answer for “not having existence or being or actuality” have?

The most common answer is nonexistent (11 letters).

Crossword clue: not having existence or being or actuality

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

nonexistent 11 letters wn-def

not having existence or being or actuality

having existence or being or actuality 80% similar → existent, existing

not having being; not existing. 50% similar → inexistent