How many letters does the top answer for “state of not being a member.” have?

The most common answer is nonmembership (13 letters).

Crossword clue: state of not being a member.

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

nonmembership 13 letters web-def

State of not being a member.

the state of not being 75% similar → nonbeing

a state of not being exposed. 60% similar → inexposure

the state of not being susceptible 60% similar → immunity, unsusceptibility