How many letters does the top answer for “another word for subtle” have?

The most common answer is insidious (9 letters).

Crossword clue: another word for subtle

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

insidious 9 letters gen-syn

working or spreading in a hidden and usually injurious way

pernicious 10 letters gen-syn

working or spreading in a hidden and usually injurious way

another word for about 50% similar → approximately, roughly, some

another word for terms 50% similar → footing

another word for under 50% similar → nether

another word for word 50% similar → phrase