How many letters does the top answer for “the act of admitting someone to enter” have?

The most common answer is admission (9 letters).

Crossword clue: the act of admitting someone to enter

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

admission 9 letters wn-def

the act of admitting someone to enter

admittance 10 letters wn-def

the act of admitting someone to enter

the act of admitting someone again 60% similar → readmission