How many letters does the top answer for “the state of being neat and smart and trim” have?

The most common answer is spruceness (10 letters).

Crossword clue: the state of being neat and smart and trim

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

spruceness 10 letters wn-def

the state of being neat and smart and trim

make neat, smart, or trim 50% similar → titivate, tittivate

the quality or state of being smart. 50% similar → smartness

the state or quality of being neat. 50% similar → neatness