How many letters does the top answer for “change from a liquid to a thickened or solid state” have?

The most common answer is clot (4 letters).

Crossword clue: change from a liquid to a thickened or solid state

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

clot 4 letters wn-def

a lump of material formed from the content of a liquid

coagulate 9 letters wn-def

change from a liquid to a thickened or solid state

changed from a solid to a liquid state 50% similar → liquified, melted