agar
noun [ U ] biology specialized uk/ˈeɪ.ɡɑːr/ us/ˈeɪ.ɡɑːr/
琼脂（海草中提取的一种透明粘稠物，可用于微生物培养基和食物增稠剂）
a thick, clear substance that comes from seaweed, used for growing organisms such as bacteria in scientific work, and also for making liquids thicker