How many letters does the top answer for “taken in advance to protect against possible danger or failure” have?

The most common answer is precautional (12 letters).

Crossword clue: taken in advance to protect against possible danger or failure

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

precautional 12 letters wn-def

taken in advance to protect against possible danger or failure

precautionary 13 letters wn-def

taken in advance to protect against possible danger or failure