How many letters does the top answer for “relating to or composed of stone” have?

The most common answer is lithic (6 letters).

Crossword clue: relating to or composed of stone

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

lithic 6 letters wn-def

relating to or composed of stone

of or relating to or composed of fat 50% similar → stearic

relating to or composed for an orchestra 50% similar → orchestral

relating to stone in the bladder. 50% similar → cystolithic