Fetching details from the dictionary...
congelation; congealment; jelly
jellied fish broth
「凝り」 has another reading with different meanings.
煮凝りは酒の肴にいい。
Aspic goes well as a drinking snack.
凝りをほぐして料理に使う。
I break up the jelly and use it in cooking.
魚の凝りは冷蔵庫で保存すると形を保つ。
Fish jelly keeps its shape when stored in the fridge.