Coagulation is the process where liquid transitions into semi-solid state or thickened, Not in the similar sense of freezing water though.
Coagulation usually happens in chunks. for example, rubber coagulates. so as your blood. basically liquid turning into solid mass. But the word is context specific. it applies to certain process only. you can say 'water congeals'.
Pudding as an example, does congeals. hope this helps :D