大脑
dà nǎo · HSK 5
brain
🧠 大 (big) + 脑 (brain) = the big brain, i.e. cerebrum
脑 is the brain organ; 大脑 literally means big brain and refers specifically to the cerebrum. Compare 小脑 (small brain = cerebellum). The 月 radical in 脑 marks body parts (flesh).
大 — pictograph of a person with arms outstretched
大 is a pictograph showing a person standing with arms and legs spread wide. The outstretched arms suggest 'big' or 'great', extending from the literal image of a large stance to abstract meanings like important or grand. It is one of the oldest characters, found on oracle bones.