How many letters does the top answer for “the operation, art, or practice of cutting for stone in the bladder.” have?

The most common answer is lithotomy (9 letters).

Crossword clue: the operation, art, or practice of cutting for stone in the bladder.

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

lithotomy 9 letters web-def

surgical removal of a stone (calculus)