How many letters does the top answer for “the trait of being cautious and watchful” have?

The most common answer is chariness (9 letters).

Crossword clue: the trait of being cautious and watchful

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

chariness 9 letters wn-def

the trait of being cautious and watchful

wariness 8 letters wn-def

the trait of being cautious and watchful

the trait of not being cautious and watchful 80% similar → unwariness